We all suffer in hot weather. However, for elderly and disabled people and those with chronic health conditions such as vascular disease or diabetes, the weather does not have to hit 100 degrees to cause heat stress or even deadly heat stroke.

As we age, we gradually lose the ability to perspire and regulate our body temperature. This is why older people tend to overdress—they don't feel heat the same way anymore. Heart rates do not speed up-or return to normal-as fast during exercise. Older skin also thins and offers less protection from the sun. Poor circulation, heart, lung and kidney diseases, and high blood pressure increase the risk for heat-related illness. Being overweight or underweight also increases risk.

Medications taken for a variety of diseases and symptoms can also interfere with one's ability to manage hotter weather. These medications include antipsychotic drugs commonly given to Alzheimer's patients to control agitation, anticholinergic drugs, tranquilizers, sedatives (including over-the-counter sleeping pills), amphetamines, diuretics and drugs to control blood pressure, antihistamines, and some antidepressants.

A person with cognitive impairment, whether from disease or injury, may not be able to communicate distress. In some cases, they may not even "feel" the heat or discomfort because of changes in the brain's abilities to process sensory information or regulate their body's responses to heat.