Fluorescent lights do not get terribly hot, they rarely affect tank temperature unless there are vast quantities of them over a tiny tank. The volume of water buffers the trend. In tanks with very little water movement it can raise the temperature of the top of the tank slightly.
Incandescent lamps do get very hot and can significantly raise tank temperatures. Usually in summer months when the water is already warm and the heater is not needing to work. If you have incandescents, then you should keep an eye on the temperature. You can add fans to the hood to vent some of the surplus heat.
You should aim to replace incandescents with fluorescent. Not only do you get rid of the heat problems, they use a lot less power to generate the same amount of light so are more efficient.