I didn’t tell her that though
Our daughter was making the 6 hour drive from her house to ours. She makes this drive at least once a year so we weren’t concerned. However, she called about an hour from my house and said that her car was close to overheating. She explained that she had checked the fluids and they were fine but that the temperature gage had been straddling the red line for over an hour now. I told her to turn off the car’s air conditioner and to turn on the heater. That would help remove heat from the engine. But, if the gage went into the red, she needed to pull over and call me. I would come get her. It was a very warm day so I cranked the air conditioner down in our house in preparation for her arrival. Sure enough, our daughter pulled into the driveway about an hour later. She was hot and uncomfortable but her car made it. She was very grateful for the air conditioning in our house. After all, she had just driven an hour with the heater blasting away in her car. We were all relieved that she was here safely. While she napped in the air conditioned house I took a look at her car. It turned out that there was nothing wrong with the cooling system at all. It was just a faulty heat sensor. So she didn’t need to run the heater in the car at all. I didn’t tell her that though. I just fixed it for her. Now she can use her air conditioning when she drives back in a week or two.