End of Fridge Freezer?

We have a Hisense Fridge Freezer that is only about 2.5 years old, but recently it has been showing errors on the temperature panel when the fridge is opened and the sides have been getting really hot. The freezer seems to be OK and the actual inside of the fridge is fine too. Is this down to the hot weather we've had in the UK recently or is there more of an unlying issue?