From marathon runners to football players to swimmers, CorTemp® will work for your athletes!

Why Monitor Temperature?

“The ability to rapidly and accurately assess core body temperature and CNS function is critical to the proper evaluation of exertional heat stroke; axillary, oral, and tympanic temperatures are not valid measures for individuals exercising in hot environments”. This statement is from a recent report on exertional heat illnesses.¹ When an exertional heat stroke is suspected the only valid option that had been available to medical staff has been rectal temperature. Today, the use of telemetry via an ingestible temperature pill offers a new approach, especially for those athletes who may be at risk for heat illnesses. The convenience of an easy-to-use field measure may prove invaluable for these individuals. [In a time of crisis (i.e. a heat stroke case) it is still necessary to have the capacity and training to be able to assess core temperature via rectal temperatures since no guarantee exists that the athlete suffering from a heat stroke will have an ingestible thermistor in their system.]

The Dangers of Exertional Heat Illnesses

During intense exercise in the heat the risk of exertional heat illnesses is ever-present. Some recent scientific manuscripts2,3,4 have outlined the keys to preventing, identifying, and treating the common exertional heat illnesses. The key to surviving exertional heat stroke is the rapid recognition of the condition (indicated by CNS dysfunction and extreme hyperthermia) and immediate initiation of ice water immersion to rapidly cool the body. Better yet, the goal should be to prevent the condition from occurring. Many intrinsic and extrinsic factors influence when the risk may be highest for an individual. These factors dictate who will benefit from using the ingestible thermistor prior to a practice or conditioning session or competition.

Key Intrinsic Factors: intensity of exercise, acclimatization state, hydration status, fitness level, history of heat illness, presence of an illness, personality, body composition, etc.

Key Extrinsic Factors: temperature, humidity, work-to-rest ratios, access to shade and fluids, education,etc.

Potential Uses with Exertional Heat Illnesses

Since the device has shown to be a valid measure of core temperature during rest, exercise (in cold, comfortable, and warm environments), and during water immersion cooling5,6,7 the following indications could be considered for an ingestible thermistor on occasions when rectal temperature is not as convenient or feasible.

• Prevention: identify rising core temperatures before they reach a dangerous level (especially useful for at-risk individuals)

• Assessment: differentiate between heat exhaustion and heat stroke without having to utilize rectal thermometers or probes

• Treatment of heat stroke: easier to monitor the core temperature decrease during ice water immersion (versus rectal temperatures)

• Body Cooling: assist athletes with timing of exit from body cooling tubs after or during practice



Prepared by:

Douglas J. Casa, PhD, ATC, FACSM

Lawrence E. Armstrong, PhD, FACSM


1) Inter-Association Task Force on Exertional Heat Illnesses Consensus Statement, NATA News, June 2003:24-29.

2) Binkley HM, Beckett J, Casa DJ, Kleiner DM, Plummer PE. National Athletic Trainers’ Association Position Statement: Exertional Heat Illnesses. Journal of Athletic Training. 2002;37(3):329-343.

3) Casa DJ, Armstrong LE. Exertional heatstroke: A medical emergency. In Armstrong, LE (ed.) Exertional Heat Illnesses. Champaign, IL: Human Kinetics: 2003:29-56, 230-234.

4) Casa DJ, Roberts WO. Considerations for the medical staff: Preventing, identifying, and treating exertional heat illnesses. In Armstrong, LE (ed.) Exertional Heat Illnesses. Champaign, IL: Human Kinetics:2003:169-196, 255-259.

5) Kolka MA, Quigley MD, Blanchard LA, Toyota DA, Stephensen LA. Vlaidation of a temperature telemetry system during moderate and strenuous exercise. Journal of Thermal Biology. 1993;18:203-210.

6) O’Brien C, Hoyt RW, Buller MJ, Castellani JW, Young AJ. Telemetry pill measurement of core temperature in humans during active heating and cooling. Medicine and Science in Sports and Exercise. 1998;30(3):468-472.

7) Sparling PB, Snow TK, Millard-Stafford ML. Monitoring core temperature during exercise: ingestible sensor vs. rectal thermistor. Aviation, Space, and Environmental Medicine. 1993;64:760-763.