Cooking Eggs With Hand Warmers

Handwarmers are great to keep your fingers functional in icy weather, but can they do more? [Greg] wondered if they could be put to good use cooking an egg, and got down to work.

The handwarmers in question are the HotHands brand, based on an iron chemistry. The warmers create their heat from the exothermic reaction between iron and oxygen that creates rust. Thus, these handwarmers need plenty of airflow to heat up. To enable this, [Greg] 3D printed a small crate with plenty of vents, into which he stacked six hand warmer sachets. An egg was nestled in the center – a perfect choice as it can be cooked in its own packaging. The pile reached temperatures of 160 F and was able to maintain that level for an hour, important as egg proteins tend to start coagulating and denaturing around 150 F. Once removed, [Greg] hoped to find a solid egg, but instead was rewarded with a somewhat gooey, semi-solid result instead. Regardless, the egg had reached an elevated temperature and shown some signs of cooking, and as [Greg] appears to be still putting out videos, we’ll assume he hasn’t yet died of salmonella.

We’d love to see this turn into an engineering competition, though, with prizes for the best cooked egg with the least amount of handwarmers. We’ve featured other egg cooking apparatus before, too. Video after the break.

27 thoughts on “Cooking Eggs With Hand Warmers

    1. They appear to have gotten paid by this ‘Greg’ fool for giving him some exposure..
      Check his yt channel and the 2 HaD articles he got this week & draw your own conclusions.

      Made a more in-detail post about it yesterday but that got removed, to me that just confirms my suspicions tbh.

  1. I wonder if the effectiveness could be achieved by tweaking the mixture, since you don’t need hours to cook an egg and the need for fresh oxygen limits the upper temperature. Alternatively, imagine placing the warmers in a pressure vessel purged, then pressurised with pure oxygen (it might be handy to have an expendable, remote building to try this out).

  2. An interesting point about salmonella. There are two very different approaches to the problem practiced in different parts of the world.
    The differences are described here: (Warning, Simon Whistler.)
    The difference is evident from where you find the eggs in the supermarket, either in the refrigerated section, or with the dry goods.

  3. I wonder if wetting the hand warmers may make it more effective?

    I’ve used MRE heaters where you add an ounce or two of water to the bag and it heats up the meal in a few minutes, the stuff inside looks basically the same as what’s in a hand warmer. Though I guess it could be a more permeable packaging allows the water in to accelerate the reaction or maybe it is a different material that just looks the same.

  4. I wonder if the foot warmers would work even better, i.e., get hotter when exposed to good airflow, since they are made to heat in the relatively airless environment of a shoe…

  5. Maybe a Haybox cooker would help with this, but then again considering the reaction needs air to work maybe not. I wonder if hitting the hand warmers with pure oxygen would speed up the reaction and release more heat?

Leave a Reply

Please be kind and respectful to help make the comments section excellent. (Comment Policy)

This site uses Akismet to reduce spam. Learn how your comment data is processed.