If you find yourself face-to-face with a hungry polar bear, it's pretty much game over.
And because of the changing climate, there could be more encounters between polar bears and people in the future, as melting Arctic ice could see the bears turn to humans as a source of food.
They are the largest land predators in the world and primarily eat seals. If the globe continues to heat, causing ice melt toward the North Pole, the bears in desperation could look to us as a way of surviving.
That's the prediction made in a scientific paper published this month called "Polar Bear Attacks on Humans: Implications of a Changing Climate," which looks at historic cases of polar bear attacks on humans.
They found 73 instances of attacks by wild polar bears between 1870 and 2014 – spread across Canada, Greenland, Norway, Russia and the U.S.
But 15 of those (20 percent) occurred from 2010-2014, a period marked by "historically low summer sea ice extent and long, ice-free periods," the report notes.
When the ice melt is particularly bad, polar bears find it more difficult to hunt the seals they rely upon for sustenance, staking out gaps in the ice floating out in sea that seals use when coming up for air. With warmer temperatures comes less ice, making it easier for seals to escape bears' clutches. This, in turn, could force them to seek food in human encampments.
"A bear's still got to eat," study author Geoff York, of Polar Bears International, told the Washington Post, "They're more likely to try new things, and sometimes, that might be us."
What to do when a polar bear attacks
Now you might know some of the basics of how to act when confronted with a brown bear (stay calm, play dead if attacked) and a black bear (make lots of noise and try to escape/fight back). Things are a little different with polar bears.
The first tip on this Mother Nature Network guide to surviving a polar bear attack is "Good luck," which gives you something of an idea what you're dealing with.
But once you've used up your luck, the website suggests you "don't act like prey" by running away (they're faster than you, so you won't get far).
They do suggest you act like a threat – which it may just ignore anyway if it's hungry, but still it's worth trying.
"Stand up straight, speak loudly and act like it should be scared of you."
Your best bet is using bear spray to ward off any potential threat, but if the bear still attacks the advice is "don't give up."
Playing dead won't stop the bear, as it wants food. And you won't beat a 1-ton polar bear in hand-to-paw combat. So all you can do is keep trying – trying to injure its nose or eyes, and staying clear of its swinging paws that can kill a person in a single strike.