On 17 Mar, 15:49, David Hansen
wrote:

I have explained why such heaters can be dangerous.

No, you haven't. You've explained the dangers of a different type of
heater.

What is likely to be the highest rated
appliance in the house and one which involves standing naked,
perhaps in a metal bath, in a stream of water which has passed over
an uninsulated heating element

Except that there isn't an uninsulated element.