When the thermostat calls for heat some how the ac comes on at the same time and the house is cold. what can I do to prevent this from happenig

My guess from the very limited info provided is a bad thermostat, either that or the thermostat was wired wrong. If you explain your problem with more detail, it may be easier to help you.

Do you have a heat pump system? Or a furnace and add on AC unit?
If you have a heat pump, it is supposed to run.
If you have furnace and add on AC system. The thermostat wire is crossed somewhere and your energizing it. For a quick fix turn off the outside breaker by the AC unit unti the spring when you can have a professional contractor look at it for you. Why freeze?