Costco has a brand called little hotties and they carry both hand and feet warmers. I always buy the hand ones for my dad he has Raynaud's syndrome so his hands are always cold. He'll use the hand size ones in his shoes if he's outside a lot, I've never gotten the foot size so I don't know how big they are compared to the hand size. Outside of the fall winter season the only place I've seen them is outdoors stores like REI, Cabellas, ect and generally they are pricy there. Which is why the Costco ones are so great the price and a big quantity can't be beat.
Thanks for the great info!! Will remember this when I move back home
