Heat: Summer’s #1 Killer

Over twenty years ago, a heat wave struck Chicago, leading to the deaths of nearly 750 people during a single week. The Chicago heat wave of 1995 tragically demonstrated that heat and humidity can be a deadly combination. These factors put a lot of stress on the human body and can lead to serious health conditions such as heat exhaustion, heat stroke, or even death. The more extreme the temperature, the shorter the amount of exposure time needed to fall ill.

Heat waves have the potential to cover a large area, exposing a high number of people to a hazardous combination of heat and humidity. In fact, heat is typically the leading cause of weather related fatalities each year. High temperatures and humidity are common in numerous locations across the country. However, when temperatures spike and humidity is on the rise in areas of the U.S. that are not accustomed to these conditions, people don’t necessarily understand that they need to take action to stay safe.

The Heat Index is a measure of how hot it really feels when relative humidity is factored in with the actual air temperature. As you can see from the chart below, high humidity levels combined with hot conditions can be extremely dangerous. Limit your outdoor activities during these periods.

The Heat Index

Here are some additional steps you can take to stay safe during a heat wave:

  • Drink plenty of water or other non-caffeinated and non-alcoholic beverages.
  • Wear loose, lightweight clothing.
  • Find a place to cool off. If you don’t have air conditioning at home then spend some time in a public location that does, like a shopping mall or a library.
  • Avoid spending time outside during the peak heat of the day (typically 10am – 3pm). If you exercise outdoors, avoid the worst of the heat by going early in the morning. If you work outdoors, check out the heat safety tips for workers from the Occupational Safety and Health Administration.

While you may think that extreme heat is not a problem where you live, heat waves can happen anywhere in the U.S., including Alaska and Hawaii. Here are several notable heat waves from across the country:

Chicago, Illinois
Notable because: this was a relatively short heat wave but it was very intense, resulting in nearly 750 deaths. Chicago, Illinois

New York City, New York
Notable because: this is the longest recorded heat wave for New York City.

New York City, New York

Atlanta, Georgia
Notable because: there were four days with highs over 103 degrees.

Atlanta, Georgia

Salt Lake City, Utah
Notable because: The high on July 26th was 107 degrees, which is the highest temperature recorded during any Salt Lake City heat wave.

Salt Lake City, Utah

Fairbanks, Alaska
Notable because: this is the longest heat wave on record for Fairbanks.

Fairbanks, Alaska

Honolulu, Hawaii
Notable because: this is the longest heat wave on record for Honolulu.

Honolulu, Hawaii

For More Information:
To learn about how to stay safe during a heat wave, visit weather.gov/heatsafety.