Hotpoint FFA70 – over heating help?

Hi

I have been reading up about the problems with this specific Hotpoint fridge freezer model FFA70, the red light coming over for “freezer high temprature” and the bit between the freezer and fridge at the front gets VERY VERY hot and also to the left of the freezer also gets VERY VERY hot, I turn up the freezer dial, it stops it for a while and then usually does it again!

This has been going on for about 3 weeks now and originally I thought it the hot weather, how ever I understand the “thermistor” maybe faulty and need replacing?
What I am not clear on is the FF series it seems you can replace the thermistor easily but the FFA models I was not to sure about?

Hope someone can help or a moderator?

Thanks. 🙂