Many people have done this, just search the forums for refrigerator or freezer. For example:
Hi all! I’ve done a lot of reading recently on setting up a fridge for dry aging meat at home and I’d like to put a humidity/temperature sensor inside the fridge so I can be alerted right away if something goes wrong. Does anyone know if the sensor will be strong enough to transmit from inside the fridge? Also, I’m thinking of using IFTTT to start a log going. Anyone have any experience with that? Suggestions? Thanks!