It's a good thought- I do keep some of those "Grabber/Mycoal" things in the vehicle anyway, for winter emergencies- it might take awhile, but it seems like you could use one to get useful water from a frozen bottle. Those readers who aren't familiar with them should know that we're not talking about the kind of handwarmer that's made of metal and burns fuel, but the kind that's essentially a gauze pad and gets its' warmth from the chemical oxidation of some pretty common, innocuous ingredients.<br><br>I have some of the old backpacker's Austrian poly bottles that I would trust to freeze, and Nalgene bottles are probably strong enough. Normally, I'd say that the typical water bottle (Evian or whatever) is plenty strong enough- they're amazingly durable- but I had one (admittedly, out of thousands) leak on me as soon as I pulled it from the shrink-wrapped six-pack, and it shook my faith somewhat.<br><br>Mabe put the plastic bottles in plastic bags for the winter, just as a failsafe... in any case, it's a good thought. Might be worth some testing. Thanks.