It can be majorly frustrating when you know where the fish are, but you can't get them to bite. This is a common occurrence for ice fisherman. Fortunately, there are things you can try before throwing in the towel.
Fish under the ice tend to be a bit lethargic. If you were as cold as they were, I imagine you would probably be, too. The slowing of their body causes metabolic changes, which forces them to move slower and typically not eat as much. This change in the fish requires that you to alter your routine. Making changes in your setup is the key if the fish aren't biting. From the live or plastic bait you choose, to the jigging, dead stick or tip-up presentation, and finished off with the use of sonar or underwater cameras. The setup you choose can turn that cold bite hot in an instant.
It's bad enough in the middle of the summer when the fish aren't biting, but throw in below zero temps, and the experience can be downright miserable. It seems no matter how cold it is outside, I barely notice if the fish are biting. The likely reason is that you don't have time to think about the cold when you are focused on the next bite. I go through a routine nearly every day on the ice that increases my chances of hooking up. There are times that the school will be in the same area and feeding on the same bait. On days such as these, you can get right to business, but more often than not you will have to adapt.