TrimixToo
Contributor
A break or crimp in any nichrome wire based vest will burn you. The Santi uses nichrome wire and every motorcycle vest I've seen uses a similar technology. And for whatever reason in a drysuit its very hard to detect/realize you have a major hotspot until you are already burnt.
There are other types like the light monkey carbon wire pads but they are arent as waterproof and typically have lower wattage overall
Sorry it wasn't clear. The point I was trying to make is that any heating design that does not allow the power to be quickly, completely, and reliably disconnected without unzipping a dry suit is a bad one.
If you get a hot spot you should be able to unplug the heated vest or undergarment or whatever. You might get a minor (maybe 2nd degree) burn while you cope, but I know someone that surfaced with 3rd degree burns on one hand because the heat could not be positively turned off or unplugged from outside the suit and there was a significant deco obligation to be discharged before surfacing.
I personally use dry gloves and wrist seals with a piece of cord under the wrist seal. If I had heated gloves I could take off the outer glove, unplug the heated glove, and pluck out the cord, but that wasn't the setup. (The reason I have things set up this way is in case I tear a glove.) That doesn't work with, say, a motorcycle vest.