From the Glacier National Park website:

Contrary to your behavior on the trail, if a grizzly bear is aggressive while you are sleeping in your tent, you must fight back with all your might.

Use anything you have as a weapon and go for the eyes and face. Outside of encountering a grizzly bear on the trail, this is the most dangerous situation to be in as the grizzly bear's aggression is likely due to hunger.


Don't pull the trigger on the spray, you will incapacitate yourself and make a bad situation much worse. On the other-hand, many bear attacks/charges are bluffs...just hope this is one of those times otherwise follow the recommended guides for black or grizzly attack.


Don't keep it in the car interior, rather in a trunk and closed container. The can I have states in capital letters: DO NOT STORE IN CAR PASSENGER COMPARTMENT.


Inadvertently if it is all you have, take the spray and use it if need be. It would be better then none as the spray would still have some effectiveness.


The bear spray I have says on the can that is good to 0C (32F). Chances are most bears are not out by time the weather gets this cool. I would (only) guess if the can is kept warm inside a jacket pocket etc, the temp range might be extended.


Can states: Safe to 50C, see above about not storing in the car where summer temps can climb above the safe zone.


Tough call on this one. Do you attempt to distract or confront the bear with a bear banger, whistles, yelling, rocks, sticks etc and risk having the bear next turn on you. If you had pepper spray, would it be worth spraying your friend along with the bear? I probably, maybe would? Chances are you will recover completely from the spray but the bear attack may be a different story..