Hot weather is a significant cause of death and illness in the United States. On the average, high outdoor temperature relates with the deaths of more than 200 Americans annually.

However, summer with sustained periods of very hot weather (heat waves) are associated with even more widespread health effects. For example, during the summer heat wave of 1980, deaths in the United States due to the heat were estimated at 1,265. Deaths during this summer's drought haven't been reported.The elderly are most likely to experience heat-related illness. For example, during the 1980 heat wave, those over age 65 were 12 to 13 times more likely to suffer from heat stroke than the rest of the population.

Infants under 1 year of age have been reported to be at high risk. Every summer, news reports announce the deaths of small children left in a locked car with windows barely open.

Certain groups of young adults may also be at high risk (i.e., military recruits, those occupationally exposed such as carpenters and laborers, and early-season football players).

Other high-risk groups include the chronically ill or bedfast, the mentally ill, those taking anti-psychotic or anti-cholinergic drugs, and alcoholics.

During heat waves, those at highest risk should avoid the heat as much as possible by staying in the coolest available place. Attending movies, "window-shopping" at an enclosed shopping mall and staying in an air-conditioned public building are options for people lacking air-conditioned residences.

Reduce physical activity during the heat, especially the hottest part of the day (11 a.m. to 3 p.m.).

Drink adequate amounts of fluids. Thirst may not be severe enough to stimulate complete fluid replacement.

Although adequate salt intake with meals is usually sufficient, salt tablets are of doubtful benefit and should not be taken unless prescribed by a physician.