Also you can use a heat lamp on a tub but you have to be careful of melting it. I use one for my daughter's leopard gecko as her room is too chilly for just a heat pad. I drilled a series of holes in the lid in a circular pattern and support the heat lamp a few inches above it. There is ever so slightly warping where the lamp is heating but not bad and you can touch it without getting a burn. Is not ideal but we are moving so I will do better one settled in to the new home. Also if your using a heat pad and a heat lamp that means 2 thermostats. Belly heat from the heat pad and ambient heat from the heat lamp are different.