Flares: These serve several purposes - signalling rescuers, lighting your way and scaring off wildlife like polar bears. Take a few.
This selfie would be crazier if this person was being eaten by a polar bear instead of watching them.
Kick It: A straight-line kick, like to the face, neck or belly, can be disorienting enough to scare a bear away. But know that it needs to be a well-placed, strong kick. A punch will do nothing.
Fact: The most carnivorous of the bear species, polar bears feed primarily on the fat of ice-dependent seals.