A common problem in bathroom lighting is using too big of lights in fixtures and placing these lights too close to the ceiling. I can’t tell you how many times I have seen the paint burnt and blistered on the ceiling above a bank of lights over a mirror. Using the thermal camera I see temperatures in excess of 100 degrees Fahrenheit. Besides being an unsightly thing this may also cause a fire. If nothing else use LED bulbs. Also be careful not to place a light over a door. Open the door to see how close the bulb is to the top edge of the door. If it is very close it may be a fire hazard. Lastly the light and all electrical connections and switches should not be within arm’s reach of the a person standing in the tub.