Freezer beneath hob?

Hi. I have asked this on another site but got no answers!
A customer has asked me if it is possible to move an integrated freezer to where the oven is now, the oven is beneath a ceramic hob.
I've never come across this before and was wondering if anyone else had?
Personally, I wouldn't do it. But I would like to know if there are any regulations or anything, so I can go back to them and say no due to this, whatever reason?

Thanks
Malc