It is very difficult to dig frozen ground, there are several options for digging it. There are two original and most common ways, one way is to stretch a tent without a bottom or just a large piece of fabric. Pre -remove all the snow from the site. Put a heater, now in Russian markets a large number of different heaters of gas, electric, various capacities are offered. After some time, more precisely, a few hours after the heater operation, you can start starting directly to the dig.