(NewsNation) — As a summer heat wave is set to hit a large swath of the Midwest and South this week, experts are urging the public to take steps to avoid potentially deadly heat exhaustion.

Temperatures are forecast to surpass 100 degrees in states including Texas, Oklahoma and Missouri from Monday through Wednesday, with some areas potentially seeing record-setting highs.

On Sunday, Salt Lake City set a new record high for July 17, reaching 104 degrees. It tied July 9 for the hottest day of the year in the city.

And in Europe, an intense heat wave has sparked wildfires in parts of Spain and France.

As the hottest part of the summer sets in, doctors are urging people to prepare for the high temperatures and educating the public on recognizing the signs of heat exhaustion.

The most important thing one can do? Drink water, and lots of it, Dr. Stacy Chronister says.

An internal medicine physician at Oklahoma State University, Chronister said many become dehydrated without even realizing it. For older people who lose water in their body more intensely, Chronister said checking your weight can be a way to watch for signs of dehydration and heat exhaustion.

“If you have lost a pound or two within a day, that’s probably water itself and you’re more likely to have heat exhaustion or stroke,” Chronister said Sunday on “NewsNation Prime.”

For younger people, fatigue is often the easiest symptom to spot.

“It’s the ‘I feel like my muscles are moving through mud’ feeling,” Chronister said. “When you start to feel like that, think water right away. Think ‘I need to hydrate myself.'”

And while the temptation may exist to do some day drinking, it’s best to avoid it, Chronister said, as it dehydrates a person faster.

“We need to make sure we are cutting back on alcohol and we are really increasing our water intake,” Chronister said. “If you know you’re going to be outside, definitely start prepping in advance.”

She recommends drinking four cups of water starting anywhere from two hours to 30 minutes before going outside.