Huh, learn something new every day!
I noticed last December work camping in Kansas that the few nights it got into the single digits I had to crank the thermostat a little colder on the fridge to keep the freezer from thawing out. I thought it was just because I had more heaters running inside the RV to keep things comfortable and one of them sat right next to the fridge and having it running 24/7 was warming up the fridge it was sitting next to. Thought it was odd but couldn't come up with a better answer until now.