What is a light bulb wired to a thermostat called and how does it work?

I'm unsure if saying things like 'wired' is correct, all I want is a light bulb that responds to the temperature. I'm using it to heat a small container where its content needs to stay around 86f, but I am worried the light bulb staying on constantly will make the area to hot(not to mention the waste in electricity) so when it reaches that temperature I want it to cut off, when it falls bellow it cuts on. I’ve searched around, but I’m unsure what its called or where to look. Thanks for any help.