A new study suggests that it may be better to immerse a heat stroke victim in temperate water rather than treat with the ice.
"Cooling in temperate water took only marginally longer than that in cold water, and one cannot imagine that the 45 (second) cooling difference would have any meaningful physiological or clinical implications," quoted Nigel Taylor, an associate professor at the University of Wollongong, as writing in a report that has been published by journal Medicine and Science in Sports and Exercise.
Working out in the heat often causes dangerous overheating amongst sportspersons, miners, and soldiers. Once a person's core temperature reaches 39.5°C to 40.5°C they get hyperthermia.
However, Taylor and his colleagues think that this may not always be practical.
"Access to ice or cold water may be limited in hot climates," the researchers write.
They even caution that sudden cold-water immersion may actually shut down the blood supply to the skin and make it harder for heat to dissipate from the body.
Taylor's team involved eight males in their study, who were heated to temperature of 39.5 degree Celsius. The subjects exercised in 36 degree Celsius and 50 per cent relative humidity while wearing a suit with 40 degree Celsius hot water pumping through it.
The researchers then compared how long it took the men to cool down in 20-22 degree Celsius air, 14 degree Celsius water and 26 degree Celsius water.
There was little difference between the effects of cold and temperate water, they said.
Taylor believes that the temperate water has a less drastic affect on the skin's blood supply than cold water, and this compensates for the fact that it is not as cold.
Dr Matt Brearley, a scientist at the Northern Territory Institute of Sport, agrees that it may be more practical to use temperate water to cool people with hyperthermia.
He, however, says that it is too early to recommend changes for heat stroke treatment.
"I'd like to see some more data on this. It's a starting point for further investigation," he says.
He says that the new findings may particularly turn out to be helpful in preventing hyperthermia sufferers in remote areas, including miners and soldiers.
"Water has such a great cooling power compared to air," says Brearley.
The researchers have received defence funding for the new study.