Sunlight is a combination of visible, UV and infrared light. Infra-red light is longer in wavelength than visible light and starts just after the visible color of red. Infra-red laser light is the safest and healthiest spectrum of sunlight and accounts for 70% of the heating of the Earth, the rest being caused by visible light. It is therefore understood that a coherent combination of visible light and infra-red laser light offers the most benefits in electromagnetic heating of objects that absorb infrared such as the human body. Other forms of heat such as fire and ceramic heaters, etc, warm a person by heating the surrounding air that touches the person which does not penetrate deeply into the body. Infra-red laser light heat penetrates the skin and is much more effective. Certain infra-red laser light wavelengths also interact with living cells increasing metabolism, energy production, and causing more fuel (calories) to be burned.