With purchases of $25 or more, Amazon offers Prime members the HotHands Hand Warmer 10-Pack for $2.75 with free shipping. (Non-members can spend $49 to bag free shipping.) That's $1 under our mention from two weeks ago, about $5 under what you'd expect to pay in local stores, and the lowest total price we've seen. Each warmer purports to last up to 18 hours.

Note that this item is part of Amazon's "Add-on program" and can only be purchased with an order of $25 or more.