Efficacy of Field Treatments to Reduce Body Core Temperature in Hyperthermic Subjects

SINCLAIR, W H. S. J RUDZKI. A S LEICHT, A L FOGARTY, S K WINTER, and M J PATTERSON. Efficacy of Field Treatments to Reduce Body Core Temperature in Hyperthermic Subjects Med Sci Sports Exerc, Vol 41, No 11 pp. 1984-1990. 2009. Purpose To contrast the effects of three postcooling techniques in reducing body core temperature (T-c) 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 tee 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-mm period (IV) Rate of decrease in T-c, 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 mm at 6 km h(-1) and 4 min at 10 km h(-1)) protocol conducted within a climate-controlled chamber (34.2 +/- 0.5 degrees C and 62.3 +/- 3.1% relative humidity) Results. Rate of T-c reduction during the first 20 min of ooling was greater for FAN compared with ICE (0.09 +/- 0.02 degrees C min(-1) vs 0.07 +/- 0.02 degrees C min(-1), P < 0.05). whereas IV did not differ with the other trials (0.08 +/- 0.01 degrees C min(-1), P > 0.05). Three participants complained of numbness or participants m 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 T-c 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 T-c cooling