Too much climate control can leave your nose dry and susceptible to nosebleeds in winter. Here's why: Four different blood vessels converge very near the surface of the septum, the wall that separates the nostrils. When the walls dry out from too much heat, blood vessels can rupture and bleed.
If you get a nosebleed, don't tilt your head back. All that does is divert blood down the back of your throat. Instead, gently pinch your nose on either side of the bridge. You're pinching too low if your nostrils close as though you had encountered something stinky.
With your head higher than the heart -- this means you should sit up -- keep your nose pinched shut for about 10 minutes so blood will clot and stop the flow. Don't let go; if you do, you'll have to start the clotting process all over.
To avoid winter nosebleeds, the American Academy of Otolaryngology suggests lubricating your septum before going to bed. Place a pea-size gob of petroleum jelly on a fingertip and rub it inside your nose.