Reviewed by TV from Oakland, CA on Tuesday, February 12, 2013
I have not had occasion to use this product yet. It looks like it should work just fine as a basic warmth retention device. They were far cheaper than what I could find locally so I bought enough to give to friends for their own emergency supplies. They are packaged reasonably well in that each is in a vented zippy bag so they are truly a "toss in the trunk/drawer/backpack" sort of item.