(WISH) — With temperatures expected to hover in the 90s this week, doctors say symptoms of heat-related illnesses can creep up fast.

Dr. Cory Showalter, who works in pediatric emergency medicine at Riley Hospital for Children, said prolonged exposure to the heat will present several symptoms, especially among kids: “Nausea, vomiting muscle cramps, acting tired, cranky, this is more common.”

Showalter says cooling down anyway possible and getting out of the sun is the best way to combat heat exhaustion and, worse, heat stroke. Signs of heat stroke include fatigue and disorientation.

“If you’re at the pool, schedule some time to get them out of the water, out of the sun, and the shade; reapply your sunblock; give them plenty to drink. Water is great but when it’s this hot kids could also use electrolyte replacement,” the doctor said.

Showalter says kids sometimes don’t realize they are suffering from heat exhaustion so parents have to keep an eye on them.

Ruby Zike found out the hard way what will happen when outside for a long time in the heat. “When I was at tennis camp I had to sit out for one game. All of us had to sit out because we were going to pass out.”

Zike was among hundreds of kids at the Franklin Family Aquatic Center on Monday afternoon in Johnson County south of Indianapolis. Many of them, including Andrew Davis, did whatever they could to stay cool.

“I like to swim in the pool and eat ice cream,” Davis said.

The doctor says parents commonly accidentally leave their children in their cars. To avoid it, he recommends giving the child a purse, a phone or a wallet to hold onto to help remember them before leaving the car.