Humidity

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...

Curious Kids is a series for children of all ages. If you have a question you’d like an expert to answer, send it to curiouskidsus@theconversation.com. My parents said the planet is getting too hot for people to live here. They called it climate change. What does that mean? – Joseph, age 12, Boise, Idaho Many countries have seen extremely hot weather lately, but in most of the inhabited world, it’s never going to get “too hot for people to live here,” especially in relatively dry climates. When it’s hot outside in dry places, most of the time our bodies can cool off by evaporating water and heat from our skin as sweat. However, there are places where it occasionally gets dangerously hot and humid, especially where hot deserts are right next to the warm ocean. When the air is humid, sweat doesn’t evaporate as quickly, so sweating doesn’t cool...

Extreme heat has been breaking records across Europe, Asia and North America, with millions of people sweltering in heat and humidity well above “normal” for days on end. Death Valley hit a temperature of 128 degrees Fahrenheit (53.3 degrees Celsius) on July 16, 2023 – not quite the world’s hottest day on record, but close. Phoenix broke a record heat streak with 19 straight days with temperatures above 110 F (43.3 C), and had more in the forecast, accompanied by several nights that never got below 90 F (32.2 C). Globally, Earth likely had its hottest week on modern record in early July. Heat waves are becoming supercharged as the climate changes – lasting longer, becoming more frequent and getting just plain hotter. One question a lot of people are asking is: “When will it get too hot for normal daily activity as we know it, even for young, healthy adults?” The answer goes beyond the temperature you see on the thermometer. It’s...