Efficacy of field treatments to reduce body core temperature in hyperthermic subjects.
OBJECTIVE
To contrast the effects of three postcooling techniques in reducing body core temperature (Tc) in exercise-induced hyperthermic participants on the cessation of exercise.


METHODS
Eleven healthy active male volunteers were cooled during a 40-min period using three different methods: ice packs to the neck, axillae, and groin (ICE); water spray and fan (FAN); and 2 L of chilled (20 degrees C) intravenous saline administered during a 20-min period (IV). Rate of decrease in Tc, cardiovascular responses, and any incidence of reported adverse effects were investigated. Trials were presented in a counterbalanced order with the volunteers' body core temperature being elevated to 40.0 degrees C on three occasions via an intermittent walk-run (2 min at 6 km x h and 4 min at 10 km x h) protocol conducted within a climate-controlled chamber (34.2 +/- 0.5 degrees C and 62.3 +/- 3.1% relative humidity).


RESULTS
Rate of Tc reduction during the first 20 min of cooling was greater for FAN compared with ICE (0.09 +/- 0.02 degrees C.min vs 0.07 +/- 0.02 degrees C.min, P < 0.05), whereas IV did not differ with the other trials (0.08 +/- 0.01 degrees C.min, P > 0.05). Three participants complained of numbness or paresthesia in their arm or hand during administration of the chilled saline, although these symptoms resolved within 5 min of ceasing the infusion.


CONCLUSIONS
All three cooling techniques reduced Tc and would be suitable for first aid application in a field setting during transportation to adequate medical facilities. Chilled IV saline did not produce any contraindications, providing a suitable alternative for Tc cooling.
Sinclair
Wade H
WH
Institute of Sport and Exercise Science, James Cook University, Townsville, Queensland, Australia. Wade.Sinclair@jcu.edu.au
Rudzki
Stephan J
SJ
Leicht
Anthony S
AS
Fogarty
Alison L
AL
Winter
Susan K
SK
Patterson
Mark J
MJ
D000328:Adult; D001831:Body Temperature / Q000502:physiology; D004638:Emergency Treatment / Q000379:methods*; D005080:Exercise Test; D005334:Fever / Q000628:therapy*; D006801:Humans; D008297:Male; D016896:Treatment Outcome; D055815:Young Adult