An intense heat wave threatens millions of people across the Southeast with temperatures reaching 115 degrees through midweek.

The soupy, smothering extreme heat that has scorched parts of the Northern Hemisphere this summer takes a hard toll on our bodies. It can make you feel nauseous, woozy and dehydrated. It can have pernicious health effects on multiple organs. But there’s another, less well-known, impact of extreme heat: It makes you age faster.