More than 300 people die each year from heat-related diseases — and thousands get very sick. The three most common heat problems can affect anyone at any age: heat rash, heat exhaustion and heat stroke — but they're 100 percent preventable. Exposure to heat plus dehydration can lead to heat exhaustion. Flu-like symptoms plus a throbbing headache, cool skin, chills and a pale, weak pulse can all occur, said Bob McNamara, chair of Emergency Medicine at Temple's School of Medicine. Treat it by drinking water and finding a cool place to sit.