During the horrific Russian winter German tankers often slept inside their tanks, tightly huddling in their seats. The famous Tigers, for instance, didn’t have a heating system so the interior of the tank could reach the same temp as the outside, sometimes -30 below.
To make the Tiger survivable it was installed with a large blowtorch to occasionally run and try to make the tank’s interior livable. The Tiger crew often went around with candle black on their faces from the torch.
The torch also doubled its use as the crews often had to use it to melt the accumulated ice and snow away from the intricate suspension every morning before they could move.
Credit: Pete Feigal (Quora)