Your drain line is clogged. You need a plumber who can auger the line all the way to the street. Do not use any chemical cleaners. They don't work and will create a dangerous hazard for the plumber. If it is really cold and the drain is clogged, it could be frozen, but if it is, it is because of the clog. Drains are normally are either empty or contain moving water, so they do not freeze.