This electric-heated vest is resistant to winter

So you're saying 5 examples are enough to prove... What exactly? This reads a lot like your opinion and I think it would be much improved if you add some sort of support and most importantly explain your reasoning. (Especially since the Dino's answer has a quote from the DMG that flat out contradicts what you are saying here which means you should really have a surplus of good evidence if you to convince is that it is wrong.)

03 DECEMBER Electric Heated Vest - Wind and Water Resistant We are about to face a terrible freezing winter. The four heaters that are woven into this vest are rated up to 12 hours of continual use. Stay Warm This Winter Keep Out The Cold Get A Vest