you can usually do that, some thermostats actually have multiple plugs other don't. when thay don't have an extra plug i usally just use an extension cord with more plugs (probably not the safest but i make sure that each heating device is around the same wattage so you don't get multiple different temps). the main think is just make sure that you don't go over the wattage that the thermostat is made for (considering there usally like 1000 watts thats not too hard lol)