Why does the Sun burn our skin?
The Short Answer: The Sun sends a few different kinds of energy to Earth. There is infrared radiation, which is heat. There is visible light, which is what our eyes can see. There is also ultraviolet light. We cant see ultraviolet with our eyes, but it can burn our skin. (NASA)  The Sun keeps our planet warm enough for living things to thrive. It gives us light so we can see. But it can also burn us. All About Energy  The Sun sends lots of energy toward us all the time. There are a few different kinds of energy. There is infrared radiation, which is heat. There is visible light, which is what our eyes can see. There is also ultraviolet light. We cant see ultraviolet with our eyes, but its there. And it can burn our skin. Waves, Waves, Waves  Infrared radiation, visible light, and ultraviolet light are all types of waves in the electromagnetic spectrum. Theyre all energy. But these energy waves arent all the same. Some have more energy than others. Infrared waves have less energy than visible light waves. Infrared waves are longer with more space between each high and low. Ultraviolet waves have more energy than visible light does. Its this energy that can hurt us. Feel the Burn  If too much ultraviolet light hits our skin, over time it can hurt our skin cells. The cells can die, and our bodies react. The skin gets red, and it can hurt a lot. Ultraviolet light comes from the Sun, but it can also bounce off of other surfaces like water, snow, and concrete. That means that even if youre under an umbrella, you can still get a sunburn. Ultraviolet light can also go through clouds, so you can get burned on an overcast day. No fair! You can protect your skin by doing things that keep ultraviolet waves from reaching you. Clothing and hats are a great way to keep away those waves. Sunblock contains chemicals that can reflect or absorb the ultraviolet light, leaving your skin sunburn free. That way you can enjoy the other energy from the Sun, visible light and infrared warmth.