Swimmers trickled into Fairview Aquatic Center in Normal when it opened its doors at four p.m.
The pool supervisor expected up to 400 swimmers to make a splash.
After the mild summer, the heat is good news for the pool.
Despite having the water to keep cool, lifeguards on duty have to keep themselves in check as well.
Lifeguards say it's a matter of being more vigilant.
"You just got to drink more water and put more sunscreen on, stay in the shade. It's not too different," added Kyle Gibson, Fairview Lifeguard.
If you're looking to cool off, Fairview Aquatic Center is open through Friday from 4 p.m to 8 p.m. and on into the Labor Day weekend from 11 a.m. to 8 p.m.
Copyright 2015 Nexstar Broadcasting, Inc. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.