Because evaporation leaves a cooler liquid, the material on which the liquid rests is cooled. Evaporation is an effective way to cool our bodies. Perspiration leaves a coating of water on our skin that evaporates, cooling the skin. Alcohol evaporates more quickly than water and has an even greater cooling effect. For that reasons parents are advised to rub alcohol on the skin of babies who are running dangerously high temperatures. It can reduce the fever and keep the baby out of danger.