About an hour ago I was driving to get petrol in my 147. Everything was fine and I've never had a problem with it. So I'm stopped at the lights for about 2 min and the temperature Gage randomly rises and I get a warning. Then I take off and it goes back to normal temperature. Then I stop again and it rises a little bit then I take off and it's fine. I'm on my way home and I stop at the same lights and the temperature doesn't rise this time. What can this be??