An ‘enclosed fixture’ means any light fitting with close-up surrounds. The issue is heat which is the enemy of LED Lights. An enclosed fixture is poor heat dissipation, they don’t allow for proper ventilation of air can affect the performance of the LED bulbs, causing overheat and shorting the lifespan of LED bulbs.
Despite the fact that the LED bulbs have similar shape to fluorescent or incandescent light bulbs, but the chip inside the LED bulbs is similar to laptops and other electronics products.Some suggest to use passive heat sink or internal fans to keep the electronics from overheating. Also, due to this reason some bulbs cant be used in an enclosed ceiling fan or enclosed porch light fixture.