Raising temperature surely is a good idea. But it is also a good idea to
address the root cause to prevent this from happening again. E.g. if indeed
it is a section on external wall that is freezing. You probably want to open
it up and add more insulation etc.
So first step is to identify the problematic sections, you can rent an
infrared camera (from some home depot, or hire some energy audit guy who has
one) to do a full home scan. This should reveal all the sub freezing areas
in your walls and floors pretty quickly.
If you know how pipes run in the wall, you may also try to use an infrared
thermometer to trace through pipe behind wall, and with some luck you might
be able to find the freezing point. Good luck