http://lifehacker.com/5718910/know-when-to-stop-exercising-when-you-have-a-cold
The best way to decide whether you should exercise is to employ what doctors call the "neck check." Feel free to go running if your cold is "above the neck." Above-the-neck symptoms include:
* Runny nose
* Nasal congestion
* Sneezing
* Sore throat
Doctors advise against proceeding with your exercise regimen if your symptoms are "below the neck," however. These symptoms include:
* Chest congestion
* Hacking cough
* Nausea or upset stomach
* High fever
* Fatigue
* Body and muscle aches