Hopefully, you haven't lost power yet and can still read a reply. A short term outage isn't a big deal. The main thing are to keep the filter media wet. With most filters that isn't a problem as the media are in water anyway. The one that you have to be careful with are Bio-Wheels where the wheel is not in water and is exposed to air. Just remove the wheel and float it in the tank until the power comes back on.
Water holds temperature very well so unless it starts to get very cold very quickly, temperature shouldn't be an issue either. If the tank temps to start to drop into the 60s, you can float bottles of hot water if you have a way to heat it such as a gas water heater or gas stove.