Captain N. E. Wickham of 4 NZ Field Ambulance:

The tented life in the field under winter conditions in Italy depresses the morale but a source of comfort to every soldier is the charcoal brazier. Charcoal is a common form of fuel in Italy and a small tin of glowing embers sheds a considerable amount of warmth in a tent or bivouac. It also gives out a certain amount of carbon monoxide but casualties from this are relatively few. The tin is energetically twirled, before dark of course, to produce a brazier full of glowing coals which will not fill the tent with smoke.