Cold laser therapy is an application of red and near-infrared light. The cold laser is very different from natural light. Unlike natural light, cold laser therapy is without heat. It is a single, wavelength beam, able to be concentrated in a small area and penetrates the skin without damage to your skin, or any known side effects. There are two types of medical lasers: high power and low power. While low-power lasers promote tissue repair and healing, high-power lasers are employed to sever tissue.