Exergen LXTA-5000 User manual

1
A kinder, gentler way to take temperatureA kinder, gentler way to take temperature
A kinder, gentler way to take temperatureA kinder, gentler way to take temperature
A kinder, gentler way to take temperature
Models LXTA/TAT-5000 and TAT-4000 Reference Manual
EXERGEN
TemporalScanner TM

2
Product Map
Product Map
Probe Cone
Probe Lens
ON Button
Automatic turn-off
in 15 seconds
LED Display Screen
Battery Compartment
9-volt battery
Battery Compartment Door
9-Volt Battery
Compartment Door Screw

3
Introduction
Introduction to Temporal Artery Thermometry
The MeThe Me
The MeThe Me
The Methodthod
thodthod
thod
Temporal artery thermometry (TAT) is a completely new method of temperature assessment,
using infrared technology to detect the heat naturally emitting from the skin surface. In addi-
tion, and of key importance, the method incorporates a patented arterial heat balance system
to automatically account for the effects of ambient temperature on the skin.
This method of temperature assessment has been shown to improve results and reduce costs
by non-invasively measuring body temperature with a degree of clinical accuracy unachievable
with any other thermometry method.
Temperatures are more reliable than with other methods. Fevers are identified sooner. Treat-
ment can be initiated sooner. We trust you will find temporal artery thermometry is simply a
better method.
WhWh
WhWh
Why the Ty the T
y the Ty the T
y the Temem
emem
emporal Arporal Ar
poral Arporal Ar
poral Artt
tt
terer
erer
eryy
yy
y
The TAT method was developed in response to the clinical requirements for a truly non-inva-
sive, accurate method of thermometry. Oral thermometry is subject to many artifactual errors;
rectal temperature meets with strong resistance from patients, parents, and even many clini-
cians. Ear thermometers, although convenient, are sensitive to technique. Some brands are
known to miss fevers, and it’s difficult to consider the use of an aural thermometer when 95%
of pediatric visits concern ear infections.
A site for detecting fevers with roots dating back to centuries before Christ, the temporal artery
demonstrated the necessary requirements to meet the stringent demands of clinical medicine
today: it is easily accessible, contains no mucous membranes, and notably, maintains a rela-
tively constant perfusion rate, ensuring the stability of blood flow required for the measure-
ment method.
As a site for temperature measurement, the temporal artery presents many benefits: it poses
no risk of injury for patient or clinician, eliminates any need for disrobing or unbundling, and is
suitable for all ages.

4
Page(s)
Product Map 2
Introduction to Temporal Artery Thermometry 3
Familiarize Yourself with the TemporalScanner 5-6
Using the Instrument 7
Using the Instrument on a New Mother 8
Using the Instrument on an Infant 9
Frequently Asked Questions 10-13
Disposable Cover Options 13
Accessories 13
Guidelines for Patient Temperature Assessment
Comparing with other methods of thermometry 14-15
Determining a Fever Threshold 16
Body Sites for Temperature Assessment
An overview of temperature measuring sites 17-18
Reproducibility in Temperature Measurement 19
Forgotten Physiology 20-21
For Kids Only 22
Care and Maintenance of the Instrument 21-25
Table of Contents
Table of Contents

5
Familiarize yourself with the Instrument
Before Using, Familiarize Yourself with the Instrument
•TT
TT
To Scano Scan
o Scano Scan
o Scan: Depress the red button. The instrument will continually scan for the highest temperature
(peak) as long as the button is depressed.
•Clicking:Clicking:
Clicking:Clicking:
Clicking: Each click indicates a rise to a higher temperature, similar to a radar detector.
•TT
TT
To Ro R
o Ro R
o Ree
ee
etain or Lock Rtain or Lock R
tain or Lock Rtain or Lock R
tain or Lock Reading:eading:
eading:eading:
eading: The reading will remain on the display as long as the red button is de-
pressed, and will lock on display for 15 seconds on the LXTA/TAT-5000, or 30 seconds on the TAT-4000
after button is released. If measuring room temperature with the TAT-4000, the temperature will remain
on the display for only 5 seconds.
•TT
TT
To Ro R
o Ro R
o Restarestar
estarestar
estart:t:
t:t:
t: Depress the button to restart. It is not necessary to wait until the display is clear, the
thermometer will immediately begin a new scan each time the button is depressed.
•Pulse Timer:Pulse Timer:
Pulse Timer:Pulse Timer:
Pulse Timer: The thermometer has a built-in pulse timer.
LXTA/TAT-5000: To activate, press the red button once and release. The display will
remain on for fifteen seconds.
TAT-4000: To activate, you should touch something >90ºF(32ºC) (skin) , press the
red button once and release. The display will remain on for 30 seconds.
The Scan
One of the most important features of the TAT thermometer is its ability to scan. It is a patented feature of the
instrument. Scanning is critical in obtaining the correct temperature, since there are temperature gradients
present not only inside the body, but across the entire surface of the body.
The object of scanning is to capture the highest temperature, the peak, in the area being scanned. As
long as the button is depressed, the thermometer will be continually sampling and recording the highest
temperature it measures.
Test it first on your hand to get comfortable with the concept.
Depress the red button, and keep it depressed. Scan the probe over the center area of your palm,
keeping the probe about a half an inch off the surface to avoid cooling the skin.
LXTA/TAT-5000: Watch the display as the temperature increases in synchrony with the clicking. When
the numbers on the display stop increasing, the clicking also stops, indicating that the
peak temperature has been reached.
TAT-4000 The display will flash SCAN, and there will be a soft but rapid clicking sound each time the
sensor detects a temperature higher than the one before. When the flashing and
clicking slow to about 1 per second, the peak temperature has been reached.
Any of the above indications can be used to assure the peak temperature has been reached. Notice on
the LXTA/TAT-5000 that the temperature only increases over the initial measurement. Once a peak has
been measured, it is locked on the display , and will not change until a higher temperature has been
measured.
Remove the instrument from your palm, release the button and note the reading on the display.
The reading will be locked on the display for 15 seconds on the LXTA/TAT-5000, and 30 seconds on the TAT-
4000, unless you press the button again before that time. Repeat the above steps and you should get the
same, or very close to the same number, since your hand will usually not appreciably change temperature
very quickly.

6
Familiarize Yourself with the Instrument
Practice Holding Your TemporalScanner
The TemporalScanner is ergonomically designed specifically for
its application. It’s best to hold the instrument with your thumb
on the red button, much like you would hold a remote control.
Along with allowing you to easily read the temperature display, you
will automatically be using finger dexterity to gently position the
probe, providing comfort and safety for your patient and consis-
tently accurate temperature readings.
Things To Know Before Taking Temperatures
•Measure only the exposed side. Anything covering the area
to be measured would insulate it and prevent the heat from
dissipating, resulting in falsely high readings. Brush hair aside
if covering the TA, or the area behind the ear.
•Slide the thermometer straight across the forehead (midline),
and not down the side of the face. Midline over the TA area,
the TA is less than 2mm below skin surface, whereas as the
TA winds down the side of the face it is further from the skin
surface. Although anatomically correct, sliding downwards
could result in falsely low readings.
•It is preferable to hold the instrument sideways, as illustrated
in Figure 2. Approaching your patient with the instrument
straight up and down could be somewhat intimidating.
•When making the measurement behind the ear as in Figure
3, tuck the thermometer under the ear lobe in the soft coni-
cal depression on the neck just below the mastoid. This is
the place where a dab of perfume is typically applied.
Using on an Infant
•An infant is apt to be presented bundled, with blankets and
clothing covering the neck area. Fortunately, the perfusion
rate is normally strong for infants, and unless visibly dia-
phoretic, one measurement at the TA is typically all that is
required.
Should you feel that the temperature is too low, push aside
any clothing or blankets covering the neck area for ~30
seconds or so and repeat the measurement behind the ear.

7
Using the Temporal
Scanner
Basics of Using the TemporalScanner
Measure only the eMeasure only the e
Measure only the eMeasure only the e
Measure only the exposed sidexposed side
xposed sidexposed side
xposed side
Brush hair aside if coBrush hair aside if co
Brush hair aside if coBrush hair aside if co
Brush hair aside if covv
vv
vering theering the
ering theering the
ering the
TT
TT
TA areaA area
A areaA area
A area
11
11
1..
..
.With probe flush on the cen-
ter of forehead, depress red
button, kk
kk
keep depressed…eep depressed…
eep depressed…eep depressed…
eep depressed…
2.2.
2.2.
2.SloSlo
SloSlo
Slowlywly
wlywly
wly slide probe midline
across forehead to the hair line,
not down side of face.
Brush hair aBrush hair a
Brush hair aBrush hair a
Brush hair aww
ww
waa
aa
ay if coy if co
y if coy if co
y if covv
vv
vering earering ear
ering earering ear
ering ear
3.3.
3.3.
3. Lift probe from forehead
and touch on the neck just
behind the ear lobe.
4.4.
4.4.
4. Release the button, read,
and record temperature.
AltAlt
AltAlt
Alternaternat
ernaternat
ernate site sit
e site sit
e sites when Tes when T
es when Tes when T
es when TA or BE are unaA or BE are una
A or BE are unaA or BE are una
A or BE are unavv
vv
vailable:ailable:
ailable:ailable:
ailable:
•FF
FF
Femoral aremoral ar
emoral aremoral ar
emoral artt
tt
terer
erer
eryy
yy
y: slowly slide the probe across groin
•LatLat
LatLat
Lateral thoracic areral thoracic ar
eral thoracic areral thoracic ar
eral thoracic artt
tt
terer
erer
eryy
yy
y: slowly scan side-to-side in the
area ˜midway between the axilla and the nipple
•AxillaAxilla
AxillaAxilla
Axilla: insert probe in apex of axilla for 2-3 seconds
Questions? Please call us at 888-838-90Questions? Please call us at 888-838-90
Questions? Please call us at 888-838-90Questions? Please call us at 888-838-90
Questions? Please call us at 888-838-9073 or 800-422-3006.73 or 800-422-3006.
73 or 800-422-3006.73 or 800-422-3006.
73 or 800-422-3006.

8
Using the Temporal
Scanner
on a New Mother
Using the TemporalScanner on a New Mother
•
Measure eMeasure e
Measure eMeasure e
Measure exposed skinxposed skin
xposed skinxposed skin
xposed skin
•KK
KK
Keep the red butteep the red butt
eep the red butteep the red butt
eep the red buttonon
onon
on
depressed thrdepressed thr
depressed thrdepressed thr
depressed throughoutoughout
oughoutoughout
oughout
measurementmeasurement
measurementmeasurement
measurement
(Brush bangs aside if present)(Brush bangs aside if present)
(Brush bangs aside if present)(Brush bangs aside if present)
(Brush bangs aside if present)
1. With prWith pr
With prWith pr
With probe flush on centobe flush on cent
obe flush on centobe flush on cent
obe flush on center of fer of f
er of fer of f
er of forehead, depress red buttorehead, depress red butt
orehead, depress red buttorehead, depress red butt
orehead, depress red buttonon
onon
on
2. SloSlo
SloSlo
Slowlywly
wlywly
wly slide prslide pr
slide prslide pr
slide probe acrobe acr
obe acrobe acr
obe across the foss the f
oss the foss the f
oss the forehead intorehead int
orehead intorehead int
orehead into the hair lineo the hair line
o the hair lineo the hair line
o the hair line
3. LifLif
LifLif
Lift prt pr
t prt pr
t probe frobe fr
obe frobe fr
obe from fom f
om fom f
om foreheadorehead
oreheadorehead
orehead
(Brush hair a(Brush hair a
(Brush hair a(Brush hair a
(Brush hair aww
ww
waa
aa
ay if coy if co
y if coy if co
y if covv
vv
vering ear)ering ear)
ering ear)ering ear)
ering ear)
4. TT
TT
Touch prouch pr
ouch prouch pr
ouch probe tobe t
obe tobe t
obe to neck just behind the ear lobeo neck just behind the ear lobe
o neck just behind the ear lobeo neck just behind the ear lobe
o neck just behind the ear lobe
5. RR
RR
Release buttelease butt
elease buttelease butt
elease button, read, and recoron, read, and recor
on, read, and recoron, read, and recor
on, read, and record td t
d td t
d temem
emem
emperatureperature
peratureperature
perature
••
••
• Temperature will remain on display for 15 seconds after the
red button is released.
••
••
• Sequence can be restarted at any time without waiting for
display to clear.
Questions? Please call us at 888-838-90Questions? Please call us at 888-838-90
Questions? Please call us at 888-838-90Questions? Please call us at 888-838-90
Questions? Please call us at 888-838-9073 or 800-422-3006.73 or 800-422-3006.
73 or 800-422-3006.73 or 800-422-3006.
73 or 800-422-3006.

9
Using the Temporal
Scanner
on an Infant
Temping Baby in Bassinette, Open Crib, or with Mom
•Instrument should be in same environment as the baby.
•Measurement site must be exposed.
•One measurement, preferably at the TA, is all that is required.
Preferred site is the temporal
artery area. In this case,
behind the ear could be an
alternate site, as both are
exposed.
Temporal artery area is
the only option in this
case, as the neck area is
not exposed.
TT
TT
Temem
emem
emperature at the Tperature at the T
perature at the Tperature at the T
perature at the Temem
emem
emporal Arporal Ar
poral Arporal Ar
poral Artt
tt
terer
erer
ery Areay Area
y Areay Area
y Area
1) Gently t1) Gently t
1) Gently t1) Gently t
1) Gently touch prouch pr
ouch prouch pr
ouch probe tobe t
obe tobe t
obe to cento cent
o cento cent
o center of fer of f
er of fer of f
er of forehead.orehead.
orehead.orehead.
orehead.
♥Depress red buttDepress red butt
Depress red buttDepress red butt
Depress red button and kon and k
on and kon and k
on and keep depressedeep depressed
eep depressedeep depressed
eep depressed ..
..
.
2) Slide pr2) Slide pr
2) Slide pr2) Slide pr
2) Slide probe oobe o
obe oobe o
obe ovv
vv
ver the Ter the T
er the Ter the T
er the TA area intA area int
A area intA area int
A area into hairline.o hairline.
o hairline.o hairline.
o hairline.
♥If more conIf more con
If more conIf more con
If more convv
vv
venient, slide frenient, slide fr
enient, slide frenient, slide fr
enient, slide from hairline tom hairline t
om hairline tom hairline t
om hairline too
oo
oww
ww
warar
arar
ards centds cent
ds centds cent
ds centerer
erer
er
of fof f
of fof f
of forehead.orehead.
orehead.orehead.
orehead.
3) R3) R
3) R3) R
3) Release buttelease butt
elease buttelease butt
elease button, remoon, remo
on, remoon, remo
on, removv
vv
ve fre fr
e fre fr
e from head, and recorom head, and recor
om head, and recorom head, and recor
om head, and record.d.
d.d.
d.
TT
TT
Temem
emem
emperature Behind the Earperature Behind the Ear
perature Behind the Earperature Behind the Ear
perature Behind the Ear
1) Gently nestle pr1) Gently nestle pr
1) Gently nestle pr1) Gently nestle pr
1) Gently nestle probe on neck behind the earobe on neck behind the ear
obe on neck behind the earobe on neck behind the ear
obe on neck behind the ear..
..
.
♥Depress red buttDepress red butt
Depress red buttDepress red butt
Depress red button and kon and k
on and kon and k
on and keep depressed.eep depressed.
eep depressed.eep depressed.
eep depressed.
2) Maintain skin contact until number2) Maintain skin contact until number
2) Maintain skin contact until number2) Maintain skin contact until number
2) Maintain skin contact until numbers sts st
s sts st
s stop.op.
op.op.
op.
3) R3) R
3) R3) R
3) Release buttelease butt
elease buttelease butt
elease button, remoon, remo
on, remoon, remo
on, removv
vv
ve fre fr
e fre fr
e from head, and recorom head, and recor
om head, and recorom head, and recor
om head, and record.d.
d.d.
d.
Questions? Please call us at 888-838-90Questions? Please call us at 888-838-90
Questions? Please call us at 888-838-90Questions? Please call us at 888-838-90
Questions? Please call us at 888-838-9073 or 800-422-3006.73 or 800-422-3006.
73 or 800-422-3006.73 or 800-422-3006.
73 or 800-422-3006.
Alternate
Site
Preferred
Site

10
Frequently Asked Questions
Frequently Asked Questions
What is the Temporal Scanner ?
The Temporal Scanner is an infrared thermometer designed for accurate, completely non-
invasive temperature assessment by scanning the temporal artery (TA).
It is breakthrough
technology .
How does it work?
Temperature is measured by gently stroking the Temporal Scanner across the forehead,
and includes a momentary touch of the probe to the neck area behind the ear lobe, to
account for any cooling of the forehead as a result of diaphoresis. The patented arterial
heat balance technology (AHB™) automatically measures the temperature of the skin sur-
face over the artery and the ambient temperature. It samples and calculates these paired
readings some 1000 times a second to control for the effect of ambient temperature on
the skin, ultimately recording the highest temperature measured (peak) during the course
of the measurement. The Temporal Scanner emits nothing - it only senses the natural
thermal radiation emitted from the skin.
How accurate is it?
It has been clinically proven in premier university hospitals to be more accurate than ear
thermometry, and better tolerated than rectal thermometry. It is a superior method for
patient and clinician alike.
What if the TA area has been traumatized by burns or lacerations, or
is completely covered with dressings?
With head trauma, surgical or accidental, the temperature can be obtained from the
alternate site behind the ear lobe. As with diaphoresis, the perfusion will be high in the
presence of head trauma.
Why measure behind the ear lobe?
Sweat causes evaporative cooling of the skin on the forehead and introduces the possibil-
ity of a false low temperature. Fortunately for the method, during diaphoresis the area on
the head behind the ear lobe will always exhibit the high blood flow necessary for the
arterial measurement.

11
Frequently Asked Questions
Why not use only the area behind the ear lobe?
Since the arterial branch is deeper behind the ear lobe than at the temple, under normal
conditions it is less accurate because of its variability. But under diaphoretic conditions, the
blood flow behind the ear lobe is as high as at the TA, making it as accurate as the TA, but
only during diaphoresis or with head trauma as previously mentioned.
What are the benefits of using temporal artery thermometry?
Besides the inherent accuracy of the method, TAT presents no risk of injury for patient or
clinician, eliminates the need for disrobing or unbundling, and is suitable for all ages.
What is arterial temperature?
Arterial temperature is the same temperature as the blood flowing from the heart via the
pulmonary artery. It is the best determinate of body temperature and is unaffected by the
artifactual errors and time delays present with oral and rectal methods.
How does the Temporal Scanner compare to our old method?
Arterial temperature is close to rectal temperature, approximately 0.8°F (0.4ºC) higher than
oral temps. Expect larger differences at times, however, as the dynamics of thermoregula-
tion favor the temporal artery method.
High readings?
Temperatures measured with the Temporal Scanner may be higher than your current method,
especially if you are used to oral or axillary temps. Oral and axillary temperatures can be
misleadingly lowered due to patient activity such as mouth breathing, drinking, tachypnea,
coughing, talking, etc., and periods of vasoconstriction during the fever process. Any or all of
these conditions may even mask fevers that the TemporalScanner will detect.
Low readings?
A patient’s temperature measured with the Temporal Scanner is normally never appreciably
lower than oral temperature. Lower temperatures are usually from scanning too fast, not
keeping the button depressed, a dirty lens, or a sweaty forehead.
What else should I know?
False high readings:
• Measure only skin that is exposed to the environment. Any covering, hair, hat, bandages,
etc., will prevent the heat from dissipating, causing the reading to be falsely high.

12
Frequently Asked Questions
False low readings:
•Multiple readings can cool the skin, so if you take another
measurement immediately, expect a slightly lower reading.
•Slide the thermometer straight across the forehead, not
down the side of the face where the TA could be embed-
ded under cartilage or fat.
•Keep the probe flush on the skin, as in the picture on the
right. If angled, you will be measuring ambient air as well
as the TA area.
Memorable solutions?
•Measure only the side exposed to the environment. The TemporalScanner as-
sumes the skin it measures has equilibrated to ambient, so a down or covered side
could be falsely high as heat is trapped and the skin is unable to equilibrate.
•If the up side is not the side closest to you, try scanning from the hairline towards
the center of the forehead.
•Scan slowly across the TA area; if you scan too quickly you can miss the peak.
Conditions that could affect a reading
•Bandages or pressure dressings covering the
forehead
•Forehead abrasions, burns, or sweat
•Agitated or combative patient
•Patient’s forehead in direct draft from vent
or fan
...and their solutions
•If accessible and dry, measure on
the area behind the ear lobe only.
•Consider using the alternate sites:
femoral artery, lateral thoracic, or
axillary areas.
•Thermometer in different ambient tempera-
ture than patient, i.e. window ledge directly
exposed to hot sun or cold weather, or in
direct line of air conditioning or fan
•The Temporal Scanner should be kept
in the same ambient temperature as
your patient. Each 10° difference in
ambient can cause a 1° error in the
reading.
○○○○○○○○○○○○○○○○○○○○○○○○○○○
○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○

13
Frequently Asked Questions
•LXTA/TAT-5000 can be used with either
disposable probe cover, cap, or sheath.
Can be used without disposables if
terminally cleaned between patients.
•TAT-4000 requires disposables.
•Can be cleaned with any hospital ap-
proved disinfectant, alcohol, and even
bleach solutions.
•Double beeping indicates a low battery.
Replace with either a 9-volt alkaline or
9-volt lithium battery.
•Probe lens should be shiny clean. If not,
wipe with an alcohol prep or Q-tip
dipped in alcohol. Occasionally follow
with a damp wipe of water to remove
any alcohol residue buildup.
•A low or high reading outside body
temperature range is indicative of the
instrument’s failsafe mode, signifying a
mechanical failure.
•Single beeping indicates ambient or
target temperature outside limits.
•Can be used in either ºC or ºF.
What should I know about the instrument
Disposable CoDisposable Co
Disposable CoDisposable Co
Disposable Covv
vv
ver Optionser Options
er Optionser Options
er Options
(Model Illustrat(Model Illustrat
(Model Illustrat(Model Illustrat
(Model Illustrated: LXTed: LXT
ed: LXTed: LXT
ed: LXTA/TA/T
A/TA/T
A/TAA
AA
ATT
TT
T-5000)-5000)
-5000)-5000)
-5000)
No CoNo Co
No CoNo Co
No Covv
vv
verer
erer
er
Terminal
Cleaning at
Patient
No CoNo Co
No CoNo Co
No Covv
vv
verer
erer
er
Disinfectant
Wipe Between
Patients
PrPr
PrPr
Probe Wobe W
obe Wobe W
obe Wraprap
raprap
rap
Covers Entire
Probe
PrPr
PrPr
Probe Capobe Cap
obe Capobe Cap
obe Cap
Covers Entire
Probe
FF
FF
Full Sheathull Sheath
ull Sheathull Sheath
ull Sheath
Covers Entire
Instrument
Accessories (Model Illustrated: TAT-4000)
1. Combination Unit
Part No. 134200
2. Instument Holder
(shown with security cable)
Part No. 134201
3. Cap Dispenser
Part No.134202
4. Disposable Caps
Part No. 134203
5. Security Cable
Part No. 124307
Model TModel T
Model TModel T
Model TAA
AA
ATT
TT
T-4000 Options-4000 Options
-4000 Options-4000 Options
-4000 Options
Model LXTModel LXT
Model LXTModel LXT
Model LXTA/TA/T
A/TA/T
A/TAA
AA
ATT
TT
T-5000 All Options-5000 All Options
-5000 All Options-5000 All Options
-5000 All Options

14
Guidelines for Patient Temperature Assessment
Guidelines for Patient Temperature Assessment
Comparing with Other Methods of Thermometry: Expect the Differences
Unless you are using PA catheters or Exergen aural thermometers with AHB for temperature as-
sessment, expect to see differences compared to your current thermometers. Arterial tempera-
ture measurement leads all other methods in identifying fever or defervescence, and is unaffected
by patient activity. Accordingly, it will be sometimes be different—but correct.
The following chart presents the range of normal temperatures at the common temperature
measurement sites under normal resting conditions.
Arterial
97.4 -100.1°F
(36.3 - 37.8°C)
Oral
96.6 - 99.5ºF
(35.9 - 37.5°C)
Esophageal
98.4 -100.0ºF
(36.9 - 37.8°C)
Rectal
97.7 - 100.3ºF
(36.5 - 37.9°C)
Oronasal
96.6 - 99.0ºF
(35.9 - 37.2ºC)
Axillary
95.5 - 98.8°F
(35.3 - 37.1°C)
Normal Body Temperature (BT)
Normal BT is not a single temperature but a range of temperatures influenced by age,
time of day, and the measurement site.
General Rule of Thumb
On a stable, resting patient, rectal temperature is ~2°F (1°C) higher than axillary and
~1°F (0.5°C ) higher than oral temperature.1
On a stable, resting patient, arterial temperature ~ rectal temperature.
Expect the Differences
Arterial temperature measurement (PA Catheter, TA Thermometry) leads all other
methods in identifying fever or defervescence, unaffected by activities of daily living. It
will sometimes be different from your present methods — but accurate.

15
Guidelines for Patient Temperature Assessment
Guidelines for Patient Temperature Assessment
11
11
1..
..
.FF
FF
Fee
ee
evv
vv
ver Defer Def
er Defer Def
er Definition:inition:
inition:inition:
inition: Clinically, fever is defined as a BT =1.8°F (1°C) above the mean standard
deviation at the site of recording.2A single oral temperature of 101°F (38.3°C ) in the absence
of obvious environmental causes is usually considered fever. An oral temperature of 100.4°F
(38.0°C ) over at least 1 hour indicates a fever state.3
2.2.
2.2.
2. Oral TOral T
Oral TOral T
Oral Temem
emem
emperature Risks:perature Risks:
perature Risks:perature Risks:
perature Risks: Oral temperature can be clinically misleading, and many febrile pa-
tients can have a “normal” temperature, even when tachypnea was unobserved.4
3.3.
3.3.
3. RR
RR
Rectal Tectal T
ectal Tectal T
ectal Temem
emem
emperature Risks:perature Risks:
perature Risks:perature Risks:
perature Risks: Rectal temperature should only be considered as a good approxi-
mation of core temperature when the patient’s thermal balance is stable. When monitored
during or after surgery, rectal temperature measurement is not suitable, and the possible delay
in diagnosis of a thermal abnormality could lead to an irreversible crisis.5
4.4.
4.4.
4. AxillarAxillar
AxillarAxillar
Axillary Ty T
y Ty T
y Temem
emem
emperature Risks:perature Risks:
perature Risks:perature Risks:
perature Risks: Axillary temperature is contraindicated in critically ill adults, and
its use in the general patient population should be discouraged due to its unreliable correlation
with core temperature and its poor reproducibility.6
5.5.
5.5.
5. TT
TT
Temem
emem
emporal Arporal Ar
poral Arporal Ar
poral Artt
tt
terer
erer
ery Ty T
y Ty T
y Temem
emem
emperature (Tperature (T
perature (Tperature (T
perature (TAA
AA
AT) VT) V
T) VT) V
T) Values:alues:
alues:alues:
alues: On a stable resting patient, TAT is ~0.8°F ( 0.4°C)
higher than an optimum oral temperature, and close to a rectal temperature.7 However, during
febrile episodes, the difference can be much higher, mainly because of the artifacts of oral and
rectal sites.
Note: If your temporal artery thermometer is marked ArterialOral,it is programmed to compute the normal
average cooling effect at the mouth, and automatically reduces the higher arterial temperature by that amount.
This allows existing protocols based on oral temperature to be maintained, and results in a reading consistent
with the mean normal oral temperature of 98.6ºF (37ºC) .
6.6.
6.6.
6. ComCom
ComCom
Comparison Beparison Be
parison Beparison Be
parison Betwtw
twtw
tween Siteen Sit
een Siteen Sit
een Sites:es:
es:es:
es: Review of published literature reveals mean differences between
non-TA sites of 0.4° to 3.1°F (0.2° to 1.7°C) with actual differences of up to 6.5°F (3.6°C )
routinely reported, especially in febrile patients.8
References:
1 Kuzucu EY. Measurement of temperature. Int Anesthesiol Clin, 3(3):435-49, May, 1965
2 El-Radhi AS, Carroll JE. Fever in Paediatric Practice, Ch 2, pp 15-49, Oxford Blackwell Scientific Publications,
1994
3 Hughes WT et al. 1997 Guidelines for the use of antimicrobial agents in neutropenic patients with unexplained
fever. Infectious Diseases Society of America (IDSA)
4 Tandberg D et al. Effect of tachypnea on the estimation of body temperature by an oral thermometer. NE J Med,
308, 945-46,1983
5 O’Grady NP, Barie PS, Bartlett JG, et al. Practice guidelines for evaluating new fever in critically ill adult patients.
Task Force of the Society of Critical Care Medicine and the Infectious Diseases Society of America. Clin Infect Dis
1998 May: 26(5):1042-59
6 Houdas Y, et al. Human body temperature. Ch 5, p89 Plenum Press, 1982, USA, UK
7 Exergen Corporation. Manufacturer’s data on file.
8 Review of subject material peer-reviewed journals.

16
Determining a Fever Threshold for Temporal Artery Thermometry
Threshold DefThreshold Def
Threshold DefThreshold Def
Threshold Defining Fining F
ining Fining F
ining Fee
ee
evv
vv
verer
erer
er
•A threshold for defining fever is the temperature above which false positives due to
normal variations in temperature, including range of normal mean + circadian effects +
other effects (metabolic, ovulation, etc.) are unlikely.
Threshold fThreshold f
Threshold fThreshold f
Threshold for For F
or For F
or Fee
ee
evv
vv
ver Wer W
er Wer W
er Woror
oror
orkk
kk
kupup
upup
up
•Not all fevers require a fever workup. A fever workup is an early management tool in
assessment of the likelihood of septicemia or bacteremia, and initiated whenever an
infectious source is suspected. The level of temperature triggering such an investigatory
workup is sufficiently high to avoid false positives resulting in unnecessary discomfort
and expense for the patient, but low enough for early identification and intervention.
PrimarPrimar
PrimarPrimar
Primary Py P
y Py P
y Pointsoints
ointsoints
oints
•Temperatures measured with temporal artery thermometry may be higher than normally
seen with other clinical methods, and therefore require an adjustment in both protocol
and perception.
•No one value can apply to every temperature measurement site. Note this old rule of
thumb: Rectal temperature is ~1°F higher than oral temperature and ~2°F higher than
axillary temperature.
•Recommended threshold for fever workup using arterial temperature assessment is a
single temperature >101.8°F or a temperature >101.2°F sustained for more than 1
hour.
•Adjustment of ~ 1°F is necessary to raise the temperature level normally mandated for
fever workups to prevent false positives, unnecessary cultures and blood tests, etc.
PhPh
PhPh
Physician Rysician R
ysician Rysician R
ysician Recommended Guidelines fecommended Guidelines f
ecommended Guidelines fecommended Guidelines f
ecommended Guidelines for For F
or For F
or Fee
ee
evv
vv
ver Wer W
er Wer W
er Woror
oror
orkk
kk
kup¹up¹
up¹up¹
up¹
Temperature Site Core &
Temporal Artery
Oral & Temporal Artery in
Oral Calibration Axillary
Fever Workup
Recommendation
Single value >101.8
Sustained values (>1h)
>101.2
Single value >101
Sustained values (>1h)
>100.4
Single value >99
¹Source on file at Exergen Corporation
Determining a Fever Threshold

17
Body Sites for Temperature Assessment
An OvAn Ov
An OvAn Ov
An Overer
erer
ervievie
vievie
view of Tw of T
w of Tw of T
w of Temem
emem
emperature Measuring Sitperature Measuring Sit
perature Measuring Sitperature Measuring Sit
perature Measuring Siteses
eses
es
Oral TOral T
Oral TOral T
Oral Temem
emem
emperatureperature
peratureperature
perature
Oral temperature measurement is by far the most common clinical method in use today, and is respon-
sible for masking the greatest number of fevers. Oral temperature can be misleadingly lowered by patient
activity such as tachypnea, coughing, moaning, drinking, eating, mouthbreathing, snoring, talking, etc.
Alarmingly, another cause of low oral temperatures is the fever itself. For each 0.6°C (1°F) temperature
elevation, the pulse rate usually increases approximately 10 beats per minute, there is a 7% increase in
oxygen consumption, and the respiratory rate increases approximately 2 cycles per minute. The resulting
increase in respiration can further lower oral temperature
sufficiently to mask a fever.
Figure 1 is of interest as it illustrates fever masking even
when clinicians had eliminated all obvious mouthbreathers
from the study. This emergency room study presents the
temperature difference (rectal minus oral) in 310 patients
with a wide range of respiratory rates. The straight line of
best fit is shown. The stippled area demonstrates the tra- d i -
tional normal difference between rectal and oral tempera-
ture (0.3°- 0.65°C). The investigators concluded, that
many patients with tachypnea would have oral tempera-
tures in the normal range despite the presence of clinical
fever, seriously misleading the clinician.
RR
RR
Rectal Tectal T
ectal Tectal T
ectal Temem
emem
emperatureperature
peratureperature
perature
Generally, rectal temperature is considered an indicator
of deep tissue and critical tissue temperatures, but long-
standing data demonstrate that rectal temperature can
be a lagging and unsatisfactory index. Fifty years ago,
Eichna et al reported differences between intracardiac,
intravascular and rectal temperatures on afebrile patients to be so insignificant that for all practical pur-
poses, the temperatures may be considered to be the same. Certainly rectal temperature is far less inva-
sive than a pulmonary artery catheter, however, in the same study, data on febrile patients support size-
able differences.
Other comparisons between rectal, esophageal and aortic temperatures undertaken on hypothermic pa-
tients by different researchers also confirm similar differences. Subsequent but equally comprehensive
comparisons on healthy volunteers further confirmed not only temperature differences, but also quanti-
fied significant lags in rectal temperature vs. hypothalamic temperature by times of order one hour. This is
of interest since the blood as it enters and affects the critical tissue in the hypothalamus should have
considerable significance in thermal homeostasis. However, this early data on hypothalamic temperature
was measured by a thermocouple inserted against (and often times perforating) the tympanic membrane.
With significant improvements in the methodology, more recent clinical observations show that the time
constant of rectal temperature in critically ill patients may be considerably longer, and in some cases as
much as a day.
Body Sites for Temperature Assessment
Figure 1 Temperature Difference (Rectal
minus Oral) in 310 Patients with a Wide
Range of Respiratory Rates. The straight line
of best fit is shown. The stippled area
demonstrates the traditional “normal” differ-
ence between rectal and oral temperature (0.3
to 0.65°C).
N = 310
r = .490
P<0.001
0
3
2
1
4
10 5020 30 40
TEMPERATURE DIFFERENCE (°C)
RESPIRATORY RATE (MIN-1)

18
Body Sites for Temperature Assessment
Under certain conditions, rectal temperature is even contraindicated; for example, severe arterial insuffi-
ciency in one or both legs might be associated with falsely low readings, or in conditions affecting periph-
eral blood flow such as cardiogenic shock. More common contraindications include neutropenia, severe
hemorrhoids, and recent anorectal surgery. A less common but serious complication of rectal temperature
measurement is perforation of the rectum, which has even occurred in the absence of predisposing rectal
pathology.
Rectal temperature measurement is not well tolerated by either the patient or the caregivers, and is un-
comfortable and embarrassing. Rectal temperature is subject to inaccuracies of placement, environment,
and time of insertion. Although it is well established that a rectal temperature requires two to five minutes
or more to reach optimum measurement with a glass mercury thermometer, in practice many are with-
drawn in just one minute, a technique responsible for misleadingly low readings.
In fact, it is difficult to attribute any thermal significance at all to the rectal area. It is not known to contain
any thermoreceptive elements and its geographical location distances it from both the CNS and the cross-
roads of circulation at the heart, which are the vital informational elements.
TT
TT
Tymym
ymym
ympanic Membrane and Ear Tpanic Membrane and Ear T
panic Membrane and Ear Tpanic Membrane and Ear T
panic Membrane and Ear Temem
emem
emperatureperature
peratureperature
perature
A temperature site of more recent onset is the ear. It is a compelling site, accessible, free from bodily
fluids, and not easily influenced by patient activity. This temperature is measured using infrared technol-
ogy, and there are three types of infrared thermometers: tympanic, ear, and arterial heat balance. It has,
however, become common practice to refer to any thermometer making the measurement at the ear as a
tympanic thermometer. Although the terms tympanic and ear may be used interchangeably, they actually
describe quite different measurements.
TT
TT
True True T
rue True T
rue Tymym
ymym
ympanic Membrane Tpanic Membrane T
panic Membrane Tpanic Membrane T
panic Membrane Temem
emem
emperatureperature
peratureperature
perature
The tympanic membrane is deep inside the skull, and is not subject to the artifactual errors that can affect
oral, rectal, axillary and ear temperatures. True tympanic thermometers provide an uncorrected, direct
reading of the temperature of the tympanic membrane, and are preferred for continual measurement
during certain surgical procedures, and for use in extreme conditions such as military use, research, and
sporting events.
There are two types of instrument used to make the measurement. One is a long thin thermocouple probe,
usually fitted with cotton at the end, that must come in contact with the tympanic membrane. There is
much historical data on the efficacy of tympanic thermometry using contact thermocouples, stemming
originally from work done over thirty years ago. However, this method never gained wide acceptance due to
the risk of injury to the delicate membrane. The other type of instrument is the Exergen Ototemp 3000SD,
which scans the tympanic membrane without contact.
Ear TEar T
Ear TEar T
Ear Temem
emem
emperatureperature
peratureperature
perature
Ear thermometry is a method of measuring the temperature of the external portion of the ear canal. For
routine clinical use, ear thermometry has been preferred as a simpler, faster, and more convenient alterna-
tive to true tympanic thermometry. The absolute temperature of the outer ear, however, is lower, and more
variable than tympanic membrane temperature. It is subject to a cooling effect resulting from the body
heat being radiated to the environment, and a heat balance method is required in order to produce the
requisite accuracy. When combined with an arterial heat balance method, ear thermometry provides a
highly accurate indication of body temperature, but those ear thermometers without it have high rates of
missed fevers.

19
Reproducibility of Readings
Reproducibility in Temperature Measurement
Multiple temperature readings in the same area, mouth, rectum, axilla, ear or temporal artery, make for
variability with each separate measurement. This can be confusing for clinicians, since they expect the
same number with each measurement. The non-reproducibility of the readings, however, is not a func-
tion of the devices, but simply a function of physiology. The human body is a myriad of small gradients,
and variability of readings will occur on every method of temperature measurement. In addition, ther-
mometers are at room temperature, nearly 30°F (17°C) cooler than the tissue being measured. That
said, it is then easily recognized how time of insertion, probe placement, and tissue cool down all affect
reproducibility of temperature readings, no matter what device is employed.
Oral TOral T
Oral TOral T
Oral Temem
emem
emperatureperature
peratureperature
perature:
By far, the most common method of temperature measure-
ment is sublingual measurements. Placement of the probe
under the tongue, however, can result in substantial
differences caused by just a slight repositioning of the
probe. The standard heat chart commonly used by manu-
facturers of electronic thermometers on the right illustrates
a difference of nearly 2°F (1°C) depending on exactly what
area is being touched by the probe.
Differences from repeated oral temperatures can vary even
further, as they can superimpose artifactual errors over the
thermal gradients. Patient activities also affect the reading,
these varying by individual and activity. In fact, one large
manufacturer cautions waiting at least 15 minutes after
ingesting hot or cold food or drink, after exposure to
extremely hot or cold weather, and after smoking.
Ear TEar T
Ear TEar T
Ear Temem
emem
emperatureperature
peratureperature
perature
The journals abound with citations addressing the lack of reproducibility of ear thermometers. In fact,
some manufactureres instruct the user to take three separate temperature measurements, and to select
the highest of the three. While much of this has to do with the device, physiology also plays a large part.
In such a small area, the difference of 30°F (17°C) between the room temperature probe and the
temperature of the ear being measured results in a noticeable tissue cool down. Geriatric patients
typically have a lower rate of perfusion than a younger individual, and it can take several minutes for the
ear to equilibrate following the use of an ear thermometer.
RR
RR
Rectal Tectal T
ectal Tectal T
ectal Temem
emem
emperatureperature
peratureperature
perature
Time and placement are critical for rectal temperature measurement. It has long been recommended
that the measurement be taken for at least five minutes or more for accuracy. The measurement is also
dependent on the depth of insertion, and just a few centimeters can result in a noticeable difference.
TT
TT
Temem
emem
emporal Arporal Ar
poral Arporal Ar
poral Artt
tt
terer
erer
ery Ty T
y Ty T
y Temem
emem
emperatureperature
peratureperature
perature
Because of the expanse of area being measured, and the normally strong perfusion of the artery in
particular, temporal artery temperatures are at least as reproducible as any other method. Of interest,
the temporal artery area will equilibrate in the shortest period of time compared to any other site. For
absolute accuracy, however, it is recommended to wait 30-60 seconds before repeating a temperature on
the same side, although, depending on the individual, the time involved can be much shorter. The
limitation in time is almost entirely the behind-the-ear measurement, as the perfusion rate per tissue
mass is not quite as high as the temporal artery. Since the method employs the area behind-the-ear with
every measurement, this area is the time limitation.

20
Forgotten Physiology
Your Temperature
Normal Temperature
Normal human temperature is
around 98.6 degrees. But did
you know that only 8% of the
people in the world have a
normal temperature of exactly
98.6?
A temperature that is normal
for you may even be a whole
degree or so above or below
“normal.” It is good to know
what is normal for you. Try
taking your temperature at
different times, like in the
morning, after a cold shower, or
after a five-mile hike.
Fever
Fever is when your body’s
temperature control is set
above normal. Fever is a sign
that your body is fighting off
an infection. It is thought that
fever does two things. When
Hot Blood or Cold Blood?
A frog in a 70 degree pond is a
70 degree frog. A frog in a 40
degree pond is a 40 degree
frog, and is moving very slowly,
if at all.
A kid in a 70 degree pond is a
98 degree kid. A kid in a 40
degree pond is still a 98 degree
kid, although you can bet he’s
swimming as fast as he can to
get out.
One difference between kids
and frogs is the difference
between warm-blooded and
cold-blooded beings. People
have automatic climate control
inside their bodies. Their
the temperature rises, the
body’s chemical actions speed
up so that damaged tissues can
be repaired more quickly. Also,
virus or bacteria invaders don’t
survive well at high tempera-
tures. Perhaps fever is the
body’s attempt to cook them
into submission.
Chills
You have a high temperature
and cold skin. You are hot
inside, but still you shiver.
Chills are your body’s way of
creating a fever. The muscle
action from shivering produces
heat, which raises your tem-
perature in an effort to fight
off infection. When the crisis
is over, your temperature is set
back to normal, the skin warms,
and you sweat.
bodies keep them at an even
temperature by carefully
controlling the rate of burning
in their cells.
Cold blooded creatures have no
internal temperature control.
Their rate of metabolism is
determined by their environ-
ment. When the outside
temperature drops way down, all
their body processes slow way
down.
Humans and all mammals are
souped-up hot-blooded beings.
Their metabolisms are speedy,
but are kept at an even keel.
So no matter what the tem-
perature is outside, the climate
on the inside is ever warm and
ready for action.1
1Exerpts from Blood and Guts: A Working Guide to Your Own Insides, Allison L, Katz D. , Little, Brown and Company, Boston, New York, Toronto, London
112º-114º
Cells begin tCells begin t
Cells begin tCells begin t
Cells begin to bo b
o bo b
o burur
urur
urn upn up
n upn up
n up
103º-104º
HH
HH
Harar
arar
ard exerd exer
d exerd exer
d exercisecise
cisecise
cise
98º-100º
”NN
NN
Noo
oo
orr
rr
rmalmal
malmal
mal”
101º
ExcitExcit
ExcitExcit
Excitementement
ementement
ement
SS
SS
Soo
oo
omeme
meme
me
activactiv
activactiv
active kidse kids
e kidse kids
e kids
106º
DD
DD
Dangeranger
angeranger
angeroo
oo
ous fus f
us fus f
us fevev
evev
everer
erer
er
96º-97º
CoCo
CoCo
Cold weather old weather o
ld weather old weather o
ld weather orr
rr
r
EarEar
EarEar
Early moly mo
ly moly mo
ly morr
rr
rningning
ningning
ning
86º
LL
LL
Loo
oo
ower limit of swer limit of s
wer limit of swer limit of s
wer limit of survivurviv
urvivurviv
urvivalal
alal
al
Frogs are cold blooded,
meaning that their
temperature changes
depending on
where
they
are.