Besides freezers I don’t think there’s any technology we know that could do this on a wide range of substances. But freezers are neat - they move heat from the inside to the outside and as they are insulated they can reach temperatures 40-50 degrees (Celsius) under their surroundings

i would think not. unless waves can be tuned to cancel out background radiation, but that would only stop it from heating up more.

I've been wondering this for my entire life

Given how much about science we still have to learn, I would say it is a distinct possibility. If you want something cheap and easy to use like a microwave to do this though, I highly doubt we'd see that possible for the next 30-40 years at minimum.

A freezer?