Heat-related illness can be a serious problem especially among older men and women. Normal physical changes as well as health concerns often combine to make high temperatures more difficult to withstand.

Problems begin to develop when the temperature exceeds 90 F for more than two or three days. When coupled with high humidity, the risks increase. These conditions keep older adults from losing heat as efficiently as younger adults and result in raising their internal body temperature. As heat builds up in the body, the early warning sign is heat exhaustion. If unrecognized and untreated, this can lead to heat stroke, hyperthermia, coma and death.

People with impaired mobility, particularly people who are bed-bound or restricted to their home; those on particular medications including ones that can impair temperature regulation and diuretics (which can lead to fluid loss); as well as people with chronic diseases or diabetes suffer most.