No cold fridge

Question

Hello there,my fridge has just decided to stop working! instead of cold it is normal air, my husband wants to throw it away and buy a new one but i dont think that the problem could be that serious.It was working last night when we went to bed but this morning we have warm cheese and lumpy milk.Any suggestions as to what we should check or do? so far we have checked the temp button. the freezer is still working.