From an interview with B-17 waist gunner Robert McBride: "about the middle to end of 1942 we got electric heat stuff to wear. Boots, socks, sweaters a lot of them. They plugged in to plugs near the gun and when they worked, they helped a good bit. But the electric cords were fragile and when things were rolling, you didn't pay a lot of attention to them and they ripped apart. They also shorted out and a wet sock against a shorted boot insert could be uncomfortable but taking your boot off at high altitude would be worse so you did your best to ignore the "hot foot" or unplugged it. The ground pounders kept adding to the things you were ordered to wear until, if you wore it all you couldn't move very well. So you made choices, according to your preferences. The rest was put in your bag so it was there if some officer came around it was there. There was also a fair amount of trade for British gear. I traded for a pair of British goggles with lamb fur around them, a pair of high flying boots which were also sheepskin lined and easier to move around in. Many of the US issue googles would fog or ice up which made shooting mighty interesting....the boots were very thick sheepskin and with two pairs of socks, one cotton one wool they didn't need electricity."