Re: Hotpoint Mistral Plus 8596 Frost free
The fridge relies on cold air being blown up from the freezer so it’s either over-iced causing a blockage to the airways or the fan motor isn’t running by the sound of it.
One way to check is to empty the whole thing and let it completely defrost for 48 hours to remove any ice, it should then work OK but if it doesn’t or it happens again within a short period, engineer time.
Repairs@ should be able to provide one if required.
Dave.