Physical activity, of course. It will warm you up in no time.
Simply don’t breathe while you are for any reason sitting down. Get up and go outside to take each breath. That routine should keep you warm and even if you forget to go outside to take a breath, you won’t feel cold since you’ll be temporarily unconscious.
I’m almost conscious on random short occasions, how do I avoid that?
You have neighbors. After Helen's done using your mallet, take it back and use it to break into your neighbor's apartment to steal their milk. If they are at home and notice you're there, charge at them with the mallet screaming hysterically until they're driven to a corner or bathroom. Take the milk, apologize and offer them some hot coco. Also, leave the mallet at their apartment in case they need anything from other neighbors.
I can't stop drinking water. What can I do? These trips to the kitchen are annoying me.
Buy two of those hellish chinese rubber toys that make weird sounds when you squeeze them. Tape them to your feet so every time you take a step, your feet will make noises. It's close enough to be considered singing.