Hi there.
Not that I am an expert, but here are my 2 cents worth
Agree fully with Francois.
I think Uncle Stan once said that if you can survive without putting on layers of clothes, so can they.
They are surprisingly hardy creatures,
I live in Raslouw, Centurion, where it regularly gets below 5 degrees in winter.
I only use my heat pads when it starts approaching those temps. I have removed them now for about a week or so.
If you do use a heat pad, just remember to put it on the side of the enclosure and not below it, so the T can regulate the amount of heat it needs by moving around.