The heat index -- how hot it really feels -- is rising faster than temperature

Researchers showed in 2022 that heat index calculations by NOAA based on analyses from the 1970s don't adequately reflect the heat stress humans feel during the extremes of heat and humidity accompanying climate change. Using their revised heat index, the researchers looked at Texas's summer 2023 heat wave and found that the 3 degree F rise in global temperatures has increased the state's heat index as much as 11 degrees F on the hottest days.