A cancelled college graduation ceremony, schools without air-conditioning shifting to virtual learning and even several deaths. This week’s potentially record-breaking heat wave has more than 100 million Americans under heat advisories, excessive heat warnings and excessive heat watches — and summer hasn’t even officially started yet. 

A large swath of the country, going as far north as Minnesota and as far east as the Carolinas is on track to hit 100 degrees, according to AccuWeather forecasts. The hot weather has only been exacerbated by a sprawling heat dome that has made its way across the West. Such weather events happen when the atmosphere traps hot air like a lid or cap.

Experts say preparing for the prolonged heat could ensure your plans aren’t ruined and your health isn’t at risk. As it heats up and many rely on fans and air conditioning, here are some tips to stay cool.

How the heat wave can impact your health

Your body is always trying to set your internal temperature, so when it’s hot outside you cool off through sweating. 

When your sweat evaporates, it takes heat away from your body. But when it’s humid, sweat has nowhere to go and doesn’t help in cooling a person off as much, Dr. Ryan Lamb, an emergency doctor and medical director at UNC Rex Hospital in Raleigh, North Carolina, told USA TODAY.

Why it’s so hot:Record-high temperatures from heat dome affect millions across U.S.

‘This is serious’:Millions under heat wave warnings as triple-digit temps move east

“The water can’t evaporate into anywhere, because it’s already in the air and so there’s nowhere for the moisture to go,” he said.

When that happens, people can start to experience heat exhaustion. While that can be mild, severe heat exhaustion — known as heatstroke — can turn deadly. Heatstroke happens when your body becomes unable to control its internal temperature.