I had a controller on my chiller lock up once with both plugs (heater and chiller) in the on position constantly. Needless to say on a 1/3 hp chiller with two 200 watt heaters running the chiller won the battle. I woke up to a tank that had condensation on the outside and the temp was down to 56 to 58 degrees depending on which thermometer was more accurate.

Slowly bring the temp back up to normal over the day and you should be fine. At 72 you really aren't in too bad of shape. I only had one casualty on that deal and it was my maroon clown.