Do I need a new car radiator?

I have a 2001 Ford Escort with 71,000 miles. A few weeks ago the car overheated on the highway. I had the thermostat replaced and since then the car had been running just fine, however, this has only been for local local trips of no more than a few miles at a time. Two days ago I had to take a long drive (just over an hour on the highway). I watched the temperature gauge carefully the whole time. There were no issues until the end of the trip when the gauge went up very high, about three quarters of the way, (a little too close for comfort). Fortunately we had just about reached our destination when that happened and we were then able to park and let the car cool for about an hour before the drive back home. On the way back, there were again no issues with the temperature gauge right up until the very end when it began to go up to the three-quarter mark. I did use the air conditioner for both drives.

This weekend I have to make a two and a half hour drive and am wondering if I should replace my radiator, or if I should just plan to drive moderately and not use the air conditioner at all. All sincere answers appreciated.

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