Infrared technology is critical in many science, business and military contexts. It makes various devices possible and useful, including night vision goggles, lasers, thermographic cameras, communications devices and weather satellites. Infrared waves are incredibly versatile, but they can also be dangerous.
TL;DR (Too Long; Didn't Read)
Infrared radiation has a longer wavelength and lower frequency than visible light. Too much exposure can damage your eyes and skin. On a global scale, trapped infrared radiation contributes to global warming.
Infrared Waves and Eye Damage
People who work in industries which expose them to infrared radiation for long periods of time may experience eye damage. The human eye is sensitive to all of the radiation in the electromagnetic spectrum, especially if that radiation is at very high levels of intensity. Exposure to intense electromagnetic radiation, including infrared radiation, can damage the lens and cornea of the eye. This is one reason why staring at the sun is harmful (and unintelligent). People who work near intense radiation must wear goggles.
Infrared Waves, Skin Damage and Lasers
Large doses of infrared waves can also damage skin and tissues. Infrared radiation waves are the same as heat waves. Laser beams are composed of highly amplified electromagnetic radiation (visible light, microwaves, infrared and others). These lasers can be strong enough to burn a hole through metal and so could certainly damage flesh. Extremely powerful lasers are even being developed by the military for use as weapons.
Infrared Waves and Greenhouse Effect
Infrared waves are involved in the greenhouse effect. The earth's surface and the clouds above it absorb radiation from the sun's rays and re-emit it as infrared radiation back out into the atmosphere. When the air above the earth's surface has a high concentration of water vapor, as well as elements such as sulfur and nitrogen and chemicals such as chlorofluorocarbons, the infrared radiation becomes trapped near the ground. This causes elevated temperatures and changes in weather patterns that can be harmful to people and animals.
More Information on Infrared Waves
On the electromagnetic radiation spectrum, infrared radiation is that which has a frequency lower than red light. These waves have longer wavelengths than visible light and make up a greater portion of sunlight than visible light and ultraviolet radiation. The heat that you feel on your face on a sunny day is caused by infrared radiation. Even your body emits infrared waves of heat, which are detectable by thermal imaging machines.