High-altitude mountain climbers do not eat snow, but always melt it first with a stove. To see why, calculate the energy absorbed from your body if you:
(a) Eat 1.0 kg of -15° C snow which your body warms to body temperature of 37°C;
(b) Melt 1.0 kg of - 15° C snow using a stove and drink the resulting 1.0 kg of water at 2°C, which your body has to warm to 37°C.