Who are EvoAIthey? Squirrels. As climate change is making extreme heat events more common, these bright-eyed and bushy-tailed critters are "splooting" to cope.

• Splooting is behavior some animals use to cool their body temperature. Squirrels are finding cool surfaces and lying on their stomachs, legs spread, to cool off.

• Think of it like finding the cool side of the pillow when you're trying to fall asleep. Sunny Corrao of the New York City Department of Parks and Recreation says it's about transferring the heat away from their bodies: 

"They're trying to find a cool space, and if they can put as much of their core body on to a cool space, then the heat is going to transfer from their bodies to the other surface. So in the case of squirrels, you'll often see them maybe on a shady sidewalk, or a park path, or in the grass, just splayed out."

• With much of the Southern U.S. under heat advisories, millions of people are facing dangerous, extreme temperatures – and when you're uncomfortable with the heat, the wildlife probably is too.

• When humans are hot, sweating cools us down. But animals that can't sweat have to resort to other behaviors to cool off. Dogs pant. Birds dunk themselves in water. And squirrels sploot. 

• But it's not just squirrels that sploot:

What's the big deal? Splooting squirrels are popping up all over social media. And while it may seem goofy and cute (it is), splooting can be a sign that squirrels are experiencing temperatures much higher than what they're used to. Climate change is making things worse.

• Carlos Botero, an associate professor of integrative biology at University of Texas at Austin, says "the temperatures we're experiencing right now are a little bit beyond the typical ability of this animal to withstand."

• Temperatures in Austin have blazed past previous records. The heat index values, or "feels-like temperature," reached their highest ever at 118 degrees. And experts say this is not normal. 

What's next? You can expect to see more splooting while extreme heat persists. But splooting can only do so much to cool squirrels down.

• Animal physiologist Andrea Rummel, an incoming assistant professor of biosciences at Rice University, says splooting is likely enough to keep squirrels cool for now. But it might not be if temperatures continue to rise, she says, because "there's only so much one avenue of heat loss can do."   

"Just like with humans. Sweating works really well a lot of the time. But if it's too humid outside and the water won't evaporate, you can sweat all you want but it won't evaporate off you and draw that heat away."

"For every kind of thermal regulatory mechanism, there is a point at which it doesn't work anymore, and that depends on environmental temperature. So it's going to get harder and harder for squirrels to sploot effectively – for humans to sweat effectively – as temperatures rise."

Learn more:

• Global heat waves show climate change and El Niño are a bad combo

• What — And Who — Is To Blame For Extreme Heat?

• How to stay safe and cool in extreme heat