Originally Posted by L473ncy
EDIT: Patcou I think I know what you're talking about. I've seen them at MEC and I have one myself. They sell under the name brand "Toasterz" at MEC, I think the solution inside is saturated sodium something or other and by popping a metal button it activates it and the liquid starts to turn hard? They're actually awesome for winter camping, I can attest to that.
Yes those are the ones i found with the metal button.