Sleeping on insulation - LOTS of blankets, plastic, cardboard between you and the insulation - that shit wreaks hell in your lungs - gotta remember, it's basically spun glass! You don't cough that back out.
Tip#1 - Raise the sleeping area... Heat rises and floors are cold!! You can use milk crates - flip em upside down. They're designed to support weight top to bottom, NOT side to side - they're less likely to collapse on you upside down, plus you get the flat surface to bed on. Tie or wire them together & they won't shift around and separate on you. (That insulation idea? ...) You can fill the inside of the crates with insulating material, insulation, foams, even balled up newspapers will help. Remember it's the trapped air that makes insulation work - so you don't want compacted fillers! Go 2 crates high & you'll do wonders for getting out of drafts and staying off cold floors.
Tip #2 - Reduce the size of the space! The larger the area you're trying to keep warm the harder it is to heat! ... Wood, or string & tarps, or even plastic - you can create false walls to reduce the area you're heating. (That insulation idea again..) Tarp + Insulation + plastic sheeting [tape together sandwiching insulation in the middle] = insulated hangable false wall
#3 be EXTREMELY cautious of where heaters are placed!!! Squatters do ridiculous amounts of "causing fires" - either flat out open flames, like candles in tents - faulty extension cords, or flame producing heaters ... Even electrics placed too near things!! Be SUPER careful with where you put your heaters... Flammable items shouldn't be within three feet of electric heaters, or five feet of flame heaters! For safety sake, don't kill yourselves trying to stay warm! Hundreds die every year like that.
Tip #4, don't try to heat with things designed to be something other than heaters... Aka, electric skillet, or what have you. They're not designed to run as long as necessary to provide sufficient heat - you will break/melt the item if you're lucky & set your squat on fire if you're not. Back to tip 3 & don't be a casualty of your own attempt to keep warm.
Tip #5, don't leave it running/burning/etc when you're not there/asleep... Yes, it's great to come back to somewhere warm - but you run a serious risk of not having somewhere to come back to if you leave heat sources unattended.
Tip #6- have a charged cell phone. Even one with no service will call 911. (Just incase ;-) )
Tip#7 - 2/3 of your bedding/blankets should be underneath you. I know it seems contrary, yet its true. That whole "ground is cold" thing... You need more to prevent the cold beneath you leeching your heat away, than you do blankets around you to keep your heat in.
Tip #8, When SAFE to do so - Sleep with as little clothing on as possible. Again, seems counter intuitive - you can have your clothes in the blanket with you (so they're warm to put back on) BUT - the less you have on your person the more effectively you will heat your bed and blanket space... You'll be warm, because the air around you will be warmed by you! Only effective if you're not trapping it all next to yourself, with tight clothing, that'll help the cold leech heat.
Tip #9 - Share your bed space! (Respectfully!) - two or more bodies will work together to heat the bed efficiently. Again minimal clothing.
... Fastest way to safely treat hypothermia is body to body contact, with insulating layered around the bodies... Never knock the benefits of a plutonic bed buddy when its winter! & If you don't trust your road dawgs this well you should probably be travelling with different people!
Tip #10 - for fuck sake - Winter Somewhere Warmer!! Lol
.... If you didn't figure it out 9 tips ago, i HATE being cold too!!! - fuck, i freeze in a house, with heaters, in Nola! (Bastards don't understand insulation at all! They compare it to putting on a down jacket in 110° heat - insisting that's what'll happen to the house come summer... Run 10 AC units & bitch constantly the units are broken.... Sigh!)