Going outside in this heat? Follow these guidelines to stay safe

Going outside in this heat? Follow these guidelines to stay safe July 2, 20266:00 AM ET Carmel Wroth People cool off at Washington Square Park during hot weather in New York City on June 29, 2026. Selçuk Acar/Anadolu/Getty Images hide caption toggle caption Selçuk Acar/Anadolu/Getty Images As the holiday weekend approaches, large swaths of the the Midwest and the Eastern U.S. are under extreme heat warnings or heat advisories, according to the National Weather Service. Heat is a serious health threat. Hundreds of people die of heat-related illness in the U.S. each year. Heatstroke can damage your body, leading to multiple organ failure or kidney failure, and it can trigger a heart attack. If you plan to spend time outdoors this week, here's a roundup of advice from NPR reporting on how to protect yourself and your loved ones. Sponsor Message For the latest stories on the science of healthy living, subscribe to NPR's Health newsletter. COMIC: How excessive heat kills and how to stay safe 1. Assess the heat risk before you go outside There's not an absolute temperature at which extreme heat turns dangerous. Rather it depends on your individual circumstances, how acclimated to heat you are and how long you're exposed to the heat, Lewis Halsey, a professor of environmental physiology at the University of Roehampton in the U.K., told NPR. Humidity is also a key factor, he says. Sweating works better to cool you off in dry heat than in humidity. Wind flow can also affect the risk of overheating. "If it's a very humid day and there's no wind speed, then you are more at risk, even if the air temperature is lower," Ashley Ward, director of Duke University's Heat Policy Innovation Hub told NPR's Life Kit. Keep an eye out for heat advisories or warnings in your area issued by the National Weather Service. These typically take into account the local heat index, which includes humidity as well as the air temperature, to get a more accurate read on how hot it will feel outside....