These mittens are made from the same windproof, water resistant fabric and engineered polymer (a specialized open cell polyurethane foam) that is used in the other clothing that we make.
These mittens are primarily designed to keep your hands warm (I know, pretty obvious!), they are not designed for heavy labor. I use mine when shoveling the walk or snow blowing the driveway. I would not use them for chopping wood or any activities that would put them at risk for snagging without a heavier, more durable shell.
The insulation and fabric combination allow warmth even if soaked through. I have taken mine and submerged them (with my hands in them) in water when the outside temperature was 15°F, took them off, wrung them out, and put them back on my hands. Within 30 seconds my hands were warm. I’ve done this multiple times under various conditions and have had the same positive result.
The mittens are part of the system, and it must be remembered that keeping your core warm is critical to keeping the extremities warm, because your personal source of heat is in your core.
(These are the mittens that come with your Bug Out Bag)