Do not use charcoal or gas grills to cook/heat indoors (carbon monoxide hazard).
If you are in a vehicle then stay on main roads.
If necessary, pull off road, stay with vehicle, use hazard signals, bright distress flag.
If trapped in blizzard, clear tail pipe, run engine/heater 10 minute each hour; open window slightly; maintain body heat (use map, seat cover, floor mat for insulation). If it is night then keep dome light on so work crews can see vehicle.