The UK is bracing for another heatwave, with forecasts predicting temperatures could reach a record-breaking 41°C next Tuesday, potentially surpassing the current record of 40.3°C set in July 2022. In such sweltering conditions, staying cool can feel nearly impossible, but a 2012 study published in the Journal of Military and Veterans' Health offers a simple, cost-free solution: consume crushed ice slushies.
The Science Behind the Slushie Hack
Exercise physiologist and researcher Matt Brearly led the study, which found that drinking equal parts crushed ice and water can effectively lower core body temperature. Unlike sugar-laden commercial slushies, this mixture uses only ice and water. The mechanism relies on the physics of phase change: ice absorbs considerably more heat as it melts inside the body, drawing warmth away before the water reaches body temperature. Crushed ice absorbs approximately three times as much heat as an equivalent amount of cold water.
Practical Application for the Public
While the study primarily recommends this method for military personnel to prevent heat exhaustion, it proves equally beneficial for anyone exposed to high temperatures. For those working outdoors or planning to exercise, drinking an ice slushy before heading out or during breaks can reduce core temperature by between 0.3 and 1.1°C. The study specifies a dosage of approximately five to seven grams of crushed ice per kilogram of body weight, to be consumed slowly about half an hour before activity.
Important Caveats
It is crucial to note that this technique is not a substitute for drinking water. During warm weather, consistent hydration remains essential to replenish fluids lost through perspiration. The slushie method is a complementary cooling strategy, not a replacement for water intake.
