June 20, one day before the official start of summer, was the hottest day of the year, with temperatures reaching up to 104 degrees. That was only the beginning, as four more 100 degree or above days and 46 days of 90 degrees or more kept the Midwest searching for ways to beat the heat.

The heat wave of ‘88 began at the end of May when the mercury in thermometers rose to 91 degrees. Since then, 48 of 91 summer days have reached temperatures of at least 90 degrees.

Allen Staver, a geography professor at NIU, said this summer’s average temperature was three degrees warmer than usual.

“It doesn’t sound like much, but it’s really quite a bit,” Staver said.

Besides causing cars to overheat and electric bills to soar, high temperatures tend to make people cranky, short-winded, and tired. Heat exhaustion and heat stroke are two major health problems associated with hot summer weather.

Heat exhaustion occurs when body fluids are lost through heavy sweating. Symptoms include muscle cramps, dizziness or fainting, headaches, and mental confusion. It can be prevented by limiting the time spent outdoors in the heat, by wearing light, loose clothing, and by drinking plenty of cool, non-alcoholic fluids.

Heat stroke occurs when the body loses its ability to eliminate heat after prolonged exposure to high temperatures. Symptoms include dizziness, loss of appetite, weakness, vomiting, and shortness of breath. If not treated quickly, it can lead to death. The critical sign of impending heat stroke is that sweating stops.