LOUISVILLE, Ky. (WDRB) -- Nothing feels better on a hot summer day than a dip in the sprinklers in downtown Louisville, which is where Betty Mills could be found Tuesday sitting in the shade with her nieces.

"She loves the water down there," Mills said of one of her nieces. "I have to beg her to get out sometimes."

But it's not all fun and games. Temperatures topped 90 degrees Tuesday with the heat index in the mid to upper-90s, making simple things like walking potentially dangerous.

"Physical exertion in the heat is a great risk factor for people this time of year with type of heat," said Dr. Karen Krigger with University of Louisville Family and Geriatric Medicine.

Doctors at U of L health care centers have seen an uptick in the number of patients coming in with heat stroke and heat exhaustion. So Krigger warns her patients to be extra vigilant.

"A heat exhaustive person will be sweating profusely. They may also have some confusion and headache," she said. "The person that's in danger of heat stroke ... they're very dry skinned."

Krigger said it can come on quickly, and those most at risk are young people, those over the age of 65, athletes and those who make a living outside like roofers, painters, construction workers and lifeguards.

Doctors say if you have to be outside for long periods of time, drink lots of water, take frequent breaks and check yourself.

"Look at your skin," Krigger said. "Are you adequately sweating, profuse sweating ... that could dehydrate you quickly and get you into to heat exhaustion. And if you stop sweating, that could be even worse. That could lead you into heat stroke."

Krigger added that you should drink lots of water before you go outside. And she warns blood pressure medications can mask some symptoms of heat exhaustion or stroke until they're severe.

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