Hello, and welcome to BYC. I used heating pads beneath the flooring in whelping boxes for many years - always made me a bit nervous. As DobieLover has stated, some do, but you could also buy a brooder plate.
Welcome to BYC.
I've used the mama heating pad several times over the past four years or so.
I raise my chicks outdoors in the coop. I've never had any problem. I have a second one on standby, but it is still in the box. I think it is as close to a broody as you can get.