Heat is a problem with LEDs.
You've heard they are cool, but that means their light has no heat. However, junction heat reduces their light output and life.
Watt for Watt, LEDs produce as much heat as an incandescent bulb. A bulb is actually cooler because it can radiate heat as IR energy, an LED cannot.
Cross Sectional View
Our standard luminaire has nearly 800 square inches of heat dissipating surface area, that's over 10 square inches per watt.