Understanding the heat index and risks

By Micki Olson, University at Albany, State University of New York The sticky combination of heat and high humidity can be more than uncomfortable — it can be deadly. Mario Tama/Getty Images You’ve probably heard people say, “It’s not the heat, it’s the humidity.” There’s a lot of truth to that phrase, and it’s important to understand it as summer temperatures rise. Humidity doesn’t just make you feel sticky and uncomfortable – it also creates extra dangerous conditions on hot days. Together, too much heat and humidity can make you sick. And in severe cases, it can cause your body to shut down. Meteorologists talk about the risk of heat and humidity using the heat index, but it can be confusing. I’m a risk communication researcher. Here’s what you need to know about the heat index and some better ways meteorologists can talk about the risks of extreme heat. Outdoor workers can be at high risk of heat illnesses. Robert Gauthier/Los Angeles Times via Getty Images What is the heat index, and how is it measured? Heat index is the combination of the actual air temperature and relative humidity: Air temperature is how hot or cold the air is, which...