Many people don’t realize how deadly heat can be. In 1995, Chicago witnessed the deadliest event in its urban history when more than 700 people died in a suffocating heat wave. Then, just eight years later, a record heat wave across Europe claimed an estimated 52,000 lives, by some reports.

Weather emergency agencies define a heat wave as a period of excessive heat that lasts for three days or more. When the body can’t cool itself through sweating and evaporation, heat-related illness may develop. What’s more, extreme heat can bring on dangerous conditions such as dehydration, sunburn, cramps, exhaustion and stroke.

In addition, when body temperature rises above 103 degrees, the heat can damage cells and cause our organs to shut down.

According to experts, we can follow simple steps to avoid these heat wave horrors: Slow down; stay out of the sun; dress in lightweight, light-colored clothing; drink plenty of water or other non-alcoholic beverages; and spend more time in air-conditioned spaces.