Greenhouse Frost Check

The weather report said it got down to 30 F. The ground temps under freezing outside. Inside the greenhouse stayed above freezing. There are 2 small space heaters on the lowest setting. When I 1st came out at 7 am they were off and the inside temp was 36.9 F. I could run them and keep it at 50 F if I really wanted to, but that’s a waste of money. As long as it’s above freezing the peppers will be fine.