The effect of immersing the hands up to the wrist in cold water to alleviate heat strain was examined in volunteers wearing chemical protective clothing and gloves. Each subject, who was monitored with skin and rectal thermistors, was observed while walking on a treadmill at two different work rates (283 +/- 47 and 455 +/- 58 watts) at 23 degrees C and at a resting state at 35 degrees C. After 20 min of work at 23 degrees C or after 120 min in the hot room, the hands were immersed in water at temperatures of 10, 15, 20, 25, and 30 degrees C. The amount of heat lost via the hands ranged between 124 +/- 14 and 31 +/- 4 watts (W) and was greater, the colder the water and harder the work. In most cases, this amount of cooling was sufficient to decrease skin temperature and lower the rate of increase of core temperature. We concluded that this method may be used to decrease resting time when working in the heat.