LED lights do not cause heat build-up; LEDs produce 3.4 btu's/hour, compared to 85 for incandescent bulbs. Because common incandescent light bulbs get hot, they contribute to heat build-up in a room. LED lights prevent this heat build-up, thereby helping to reduce air conditioning costs in the home. Mercury-free - no mercury is used in the manufacturing of LED lights. Efficient- LED lights use less watts (1/3rd to 1/30th of Incandescent or CFL). LED light save electricity, remain cool and save money on replacement costs since LED light bulbs last so long. LED Lights will extend battery life 10 to 15 times longer. Choose "LED" lighting and save -- MONEY, ENERGY, and the ENVIRONMENT.