How hot should the back of a freezer get?!

[NDA]

I have a fairly new Zanussi stand alone freezer, it went wrong after about 9 months and had to have the compressor replaced. Not impressed.

It's now decided to defrost itself and has ruined a load of food, I'm not entirely sure why it's done this and there was no warning light.

Mess cleaned up and it seems to be running, but the back of it is almost too hot to touch (can touch for 2 seconds).

How warm are they supposed to get?

Thanks......