This is the warm tingly feeling that you experience when you walk out into natural sunlight. Having an internal reflector means far less of the heat is wasted. It also heats up very quickly, reaching target basking temperature in a fraction of the usual time. The Arcadia Deep Heat Projector produces virtually no visible light and can be used throughout the day and night. Reptiles associate heat with high levels of light in the day, as such The Arcadia Reptile Deep Heat Projector is ideal for use alongside Arcadia Reptile UVB systems and Arcadia Jungle Dawn LED plant growth systems. The Deep Heat Projector should be used with a dimming thermostat which will provide you with accurate control of your thermogradient.