Dr. Paul Auerbach is the world's leading outdoor health expert. His blog offers tips on outdoor safety and advice on how to handle wilderness emergencies.
See all posts » The summer has begun, and with it comes the seasonal onset of heat waves. We've been suffering through high environmental temperatures recently, and with global warming, it's likely that very hot summers will be the rule rather than the exception. Humidity makes the situation worse, as it impedes evaporation of sweat, which is a major body cooling mechanism for humans. The National Weather Service has a heat index that roughly correlates air temperature and relative humidity to derive an "apparent temperature." At all temperatures, humidity makes the situation worse. For instance, at an air temperature of 85 degrees Fahrenheit, if the relative humidity is 80%, the apparent temperature is 97 degrees F. So, you must be extremely careful not to overdo it when the thermometer is rising.
The most effective ways to avoid heat-related illnesses are to:
