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 Conjunctivitis. Viruses can cause conjunctivitis, such as the familiar red eyes, sore throat, and runny nose of a common cold. Viral conjunctivitis usually produces a watery mucous discharge and lasts from 1 to 2 weeks. Infectious conjunctivitis, commonly known as pink eye, can be quite contagious.