The heater may be a 100 watts. and the lights may be 250 watts, but you need to check the amps, how many amp are they. The normal outlet can handle "x" amount of amp running from it. Look at your equipment see the amps add them up. If it more that the outlet can handle, then try to runn some of the equipment on other outlets or other circuits. If you run more amps off a line than it can handle you will continuously trip your circuit, or worse yet risk a fire starting.