Like humans who spend too much of Labor Day weekend catching the last of summer’s rays, whales who spend a lot of time on the surface can get sunburned. But while we slather sunscreen on our skin, whales don’t have the hands or the technology to do the same. So, researchers are looking at different species of whales to see how they burn, and what they do about it.

As you might expect, how fair a whale’s skin is and how much time it spends near the sun impact how much it burns. Blue whales are pale but don’t spend a ton of time at the surface. Sperm whales have somewhat darker skin but spend a lot of time at the surface between feeding. Fin whales are dark, and rarely burned.

Much like ours, blue whales’ skin tries to protect it from harmful UV rays by getting tan—the pigmentation of their skin changes. But sperm whales do something a little different. Here’s the Newcastle University press office:

The scientists found the sperm whales had a different mechanism for protecting themselves from the sun, triggering a stress response in their genes. Newcastle University researcher Amy Bowman added: “We saw for the first time evidence of genotoxic pathways being activated in the cells of the whales – this is similar to the damage response caused by free radicals in human skin which is our protective mechanism against sun damage.”

Basically, the generation of free radicals is bad for us (and for whales). Our bodies burn to limit this process: it’s the body’s way of keeping the UV rays from creating free radicals and breaking down our DNA.

As you might expect, studying skin damage on migrating whales isn’t easy. Researchers had to take skin samples from whales in the wild, which is no walk in the park. And because no one has a record of whales skin issues before now, scientists don’t know if they’re getting more sunburned now than they had been in the past or not.

More from Smithsonian.com:

Ask an Expert: Do Animals Get Sunburned?

Did Scientists Just Discover a Cure for Sunburn Pain?