Infrared heat may be a hot new trend in grilling, but this type of heat has been occurring naturally since the dawn of time. In fact, everything with a temperature above absolute zero (which is equal to -459.67 degrees Fahrenheit or -273.15 degrees Celsius) emits at least a little infrared radiation.
For example, bacterial and viral causes of pinkeye are almost always contagious and are spread from person to person. However, pinkeye caused by allergens and chemical irritants is not contagious by person-to-person contact. Pinkeye that is contagious has an incubation period as long as 14 days. However, most doctors do not think that pinkeye becomes contagious to other people until symptoms start to develop.
Viral pinkeye symptoms usually last 5 to 7 days but may last up to 3 weeks and can become ongoing or chronic. Pinkeye may be more serious if you: 1  Have a condition that decreases your body's ability to fight infection (impaired immune system).t usually is not serious and goes away in 7 to 10 days without medical treatment. Most cases of pinkeye are caused by: 1  Infections caused by viruses or bacteria. 2  Dry eyes from lack of tears or exposure to wind and sun. 3  Chemicals, fumes, or smoke (chemical conjunctivitis).