Like the other reviewer stated; this thing is worthless. I bought it from a Dick's store and it didn't heat up at all! Do not buy this hand warmer!

The Firepod is spec'd to heat to 150 degrees. I put it in the box it was shipped in, with some foam insulation and a digital thermometer. After 30 minutes it reached 74 degrees (inside temp of the house was 69 degrees). The package from Optronics stated a 100% customer guarantee. I sent it to Optronics with the original package that had the guarantee written on it, with a note to replace it with a good working unit or refund my purchase price. They sent me another unit. Testing this time showed it reach a temperature of 80 degrees after 30 minutes. They did not send any packaging so I don't have a written guarantee any more. The cost to send it back a second time will total more than than the original cost. I have now seen reviews on other web sites with similar experiences. Don't waste your money on this product.