Here's one more reason to consider investing in energy-efficient LED lightbulbs for your home: They won't mess with your thermostat. Incandescent, halogen and even CFL bulbs emit heat when they are turned on. If you have a lamp with one of these bulbs near your thermostat, it will sense the heat and assume that's the temperature of the room. In the winter, it will keep the house too cold, and in the summer, it will overwork to keep the house cool. With LED bulbs, you get the benefits of clean, bright light but with zero heat; LED bulbs do not produce heat and stay cool to the touch. Plus, many LED bulbs will last 20 to 25 years before needing to be replaced.