Sounds like the outlet was a switched wall outlet controlled by the switch. Is one side of the outlet controlled by the switch? The switch is damaged and needs replacement. The heater and whatever else was plugged into the outlet overloaded the circuit. Since the circuit breaker did not open I would think that the wiring is ok. If you had to ask this question I suspect you have little or no experience with home hi-voltage wiring. The very best thing you can do is get an electrician to replace the switch. He can also test the line back to the panel to check for partial shorts and check the wall outlet to be sure it was not damaged.