How Hot is Too Hot to Exercise Outside?

Because Pennsylvania has long-lasting winters and cold weather that often lingers into springtime, everyone wants to be outside as much as possible when summertime emerges.

Exercising in the warm weather can be beneficial for your health. But, if the weather is too hot, exercising and playing sports outside can be dangerous.

Keri Peterson, MD, and medical advisor for Women’s Health said the health risks of exercising outdoors during hot, humid weather far outweigh the benefits. When you work out in extremely hot temperatures, your body sweats more to cool itself, causing your blood pressure to drop and heart rate go up. This can lead to lightheadedness. When your body temperature continues to rise, you can put yourself at risk for heat stroke, seizures, and heart rhythm problems.

The temperature at which you should refrain from exercising outdoors isn’t an exact number. The combination of heat and humidity is what can create a dangerous environment for your body.

To gauge when you should hit the indoor gym instead, Peterson recommends using a heat index, which uses both temperature and humidity levels to calculate how hot it really feels outside.

The thermometer might say it’s only 84 degrees outside. However, if the humidity is at 75 percent, the heat index estimates that it feels like it is actually 92 degrees outside. When the heat index hits 90 degrees, you are outside the threshold for outdoor activity and should stay indoors.

Try to make a habit of checking the current heat index map in your area, such as this one from The Weather Channel. That way, you aren’t putting yourself at risk.

Although the 90-degree heat index rule says stay inside, your body may be different than the average. Your weight, fitness level, and health status could make the heat limit even lower.

When you are exercising outside this summer, assess your body and monitor your perspiration for signs of dehydration to make sure you are exercising safely!