On hot days, taking to the pool is how humans cool off.  It turns out, animals, at least at the Lehigh Valley Zoo, feel the same way.

Believe it or not, however, penguins swimming around at the zoo aren't doing it to cool off.

"The penguins from southwestern Africa like warmer temperature," said Hannah Fullmer, of the Lehigh Valley Zoo said.

That's the exact opposite of a snow owl, which basically bakes beneath a parka of feathers.

"So we do give him blocks of ice and ice chips. We mist him to keep him cool," said Joe Proto, of the Lehigh Valley Zoo.

Fullmer and Proto are tasked with braving the heat and making sure the animals stay cool, which includes fish blood ice cubes for otters and iced fish for the Mexican grey wolves.

"Everyone gets fresh water, and if we know it's going to be a hot week, we have more pre-made treats and ready to go," said Fullmer. "We have a freezer-full tomorrow."

When animals really feel the heat, Fullmer said they'll let you know.

"Big open mouth when breathing. We do know something," she said.

For penguins, Fullmer said a bright red or pink spot above their eye is an indication the heat is getting too much.

In the heat, herbivores, she said, conserve energy, while temperatures can't contain carnivores.