P0303 code and engine light

[beerdog1]

I had a new experience with my car today. When I started the car today it immediately threw this engine light and a P0303 Cylinder 3 misfire code. The car ran rough and had very little power. The manual stated it was safe to drive so I drove about 25 miles. I had very little choice. I stopped after about 22 miles to get gas. The car ran perfect after restarting the car and has not exhibited the problem again today.

I live in Chicago and was parked outside overnight. It was in the 20's last night.

I have been reading posts on misfire codes. Anyone have anything to add besides maybe checking the plugs?