The Norovirus attacks the stomach, bringing about numerous symptoms such as vomiting, diarrhea, horrific stomach pains, cold sweats, hot flashes, hives, fevers, etc. Not to get too personal here but I can tell you first hand that this virus is no joke. I was in more pain from this one virus than I have been during my numerous dairy allergy attacks, which have sent me to the hospital. Unfortunately, one of the only things that the hospitals can do is to insert an IV in order to help hydrate the patient. While that is extremely important to be hydrated and is a requirement once liquids can be kept down, I would leave the choice to go to the hospital up to the patient.
For anyone who is worried about this, do not fret. Stress will lower your immune system. By keeping yourself healthy, you will boost your immune system and thereby help to set your defenses against these illnesses.
If you do catch this stomach virus, don't worry. Even though at the time it may not feel like it, it WILL pass. The worst part of it lasts for 12 hours and the overall recovery varies per person. Just keep an optimistic mind and drink water and electrolytes.
Good luck stomachs!
Here are a few articles that explain a bit more about the virus: