Some like it hot

Recently, we've had a few calls where people have lost power in parts of the house.  Either due to cold, or a furnace problem, they were using multiple electric heaters.  Even in different rooms, they can end up on the same circuit and a circuit breaker can typically only handle one plug-in heater. 
At least the solution is easy:   Unplug the heaters, reset the breaker (it may not look like it's tripped so you do each individual one - click Off, then On), and plug in just one heater, and/or use them at different times.