Numb out no more! Black Diamond’s Hot Forge chalk bag is a one-of-a-kind chalk bag with a heating element inside, designed for colder-weather climbing. It’s perfect for a conditions-dependent redpoint where you’d want as chilly as you can stan. With an internal heating systems that warms your digits every time you chalk, this unique chalk bag helps take the edge off and keeps your hands from going numb. Even if you’re just looking to squeeze a few extra days out of the season, on either end, this would do the trick.

Should you buy it? If you have ever numbed out on a route, then yes. If you have poor circulation in your hands–i.e., people with Reynaud’s—definitely yes. If you want to squeeze one more pitch out of the end-of-season days, yes! This is a great item in the quiver of cold-weather climbers’ bag of tricks. However, the Black Diamond Hot Forge Chalk Bag only gets so hot, so don’t expect it to be quite as toasty as a disposable hand warmer.

Where to Buy

Exclusively at Black Diamond

Black Diamond Hot Forge Specs

  • Insulated baffles (8g Thinsulate)

  • Weight: 175 grams (with battery)

  • Battery Life with Full Charge:

    • Low: 6-8 hours

    • Med: 4-6 hours

    • High: 2 hours

  • $69.95 MSRP



What I like

  • The design is slick and subtle, and the heating element itself is not very noticeable in its pouch. That is, it doesn’t feel bulky or clunky or anything like that. 
  • I like that the bag itself is insulated. What helped the bag feel even warmer was turning it on 10 minutes or so prior to tying in. 
  • Speaking of turning on, the button and settings were easy to use–red was the warmest, then yellow, then green. Charging is also easy. 
  • Functionally speaking, when it’s not cold the bag still works as a chalk bag. You don’t need to just use this on cold days. Like the Mitch Hedberg joke “Escalators can never break, they can only temporarily become stairs”. 
  • The heat source feels different and more uniform than a hot pack in your chalk bag.
  • Not having to use hot packs every session.

What I don't like

  • $69.95 is a bit steep for a chalk bag, but if you factor in the savings on hot packs over a winter season it might even out. 
  • The size: I don’t have huge hands, and yet even for me the pouch felt cramped enough with the heating element in there, I wasn’t able to get my thumb in comfortably as well. 
  • Charging system requires a not-sold-separately wall charger, which if lost or broken, renders the chalk bag, well, a normal albeit expensive chalk bag. 
  • Hottest setting still seemed not as warm as a hot pack. 



How I tested it

 Climbed several cold cloudy winter days at the Puoux, CO, the backyard crag. With highs of mid 30s and no sun, the days were COLD. I would like to take it on a multi-pitch in the future to see how it would fare. 

Other options to consider

The Hot Forge chalk bag is unique and goes a long way in extending those colder outdoor sessions. While it could improve with some modest tweaks, I recommend it for anyone looking to be a bit more comfortable on the tail ends of the season. 

    Suggested reading: “The Evening Sends Guide to Choosing Climbing Shoes”