Is there a quick and painless way to find the wattage on a very very hot bulb that I can't turn off?

My Uromastyx lizard’s cage is running a bit hot with the change in temp. He’s extremely susceptible to cold, though, so I don’t want to shut off his primary heating lamp for the time it would take for it to cool down enough for me to take it out and examine the bulb for any writing on it. I need to go out and get a slightly lower wattage bulb for the summer, but I don’t know what the wattage of this current one is. These bulbs are REALLY expensive, so I can’t guess and check. According to my laser tempgun the bulb itself is over 400 degrees F on its surface. Any way that I can figure out the wattage without having to sneak it out silently in the night, go find a light, and examine it?