Treating a sunburn with more light may seem counter-intuitive, but it makes a lot of sense when you understand the science. Sunburns are caused by ultra violet light (in the wavelength spectrum of 290nm to 380nm). There are other wavelengths of light that are helpful to your body. This is light that your cells can take in to help them heal faster. These helpful wavelengths include red (630nm to 660nm) and infrared (830nm to 880nm).
When skin is damaged by too much exposure to UV light, you get a sunburn. Exposing that same skin to only the helpful wavelengths of light can help those damaged tissues to heal faster. We have seen sunburns that looked destined to peel turn instead into a nice tan. So yes, sometimes a great way to treat a sunburn is with more light, it just has to be the right type of light.