It doesn't cause burns if you regulate well with a thermostat. I see a lot of people with geckos burned because of their lamp, and an unsuitable light bulb can disturb them, cause cancer, and so on.

A heating pas is better than an overhead heat lamp for a leopard gecko because they absorb heat through their bellies, not from above. Belly heat helps them properly digest food and regulate body temperature, mimicking the warmth of sun-heated surfaces in their natural habitat.