It depends on their design
Answered by Rupert, Electrical Safety Expert
It depends on their design.
As long as the heated mirrors and towel rails conform to the relevant British standard (BS EN 60335 series) the manufacturer’s instructions will give guidance on where they can be located.
Please note that if you are fitting a new appliance on a new circuit in a special location such as a bathroom is notifiable work.
For this type of work, we would always recommend that you use a registered electrician. This gives you the peace of mind that if something does go wrong, the work is insured and their scheme operator can help you if you are not satisfied.
You can find an electrician local to you here.