I've got 10, I think, 40 hour ones. I ordered them online. Not sure on local, but sporting goods stores might have some. You just need to watch out for the shorter lived ones, as those get too hot quickly, then run out of juice. So, you cook the corals, then let them freeze.
If you want to wait til friday, I can bring a few over to the meeting. Just let me know how many you want.