What should I do to stay calm?

Pray for the well being of your friend.

Well personally there are many ways I choose to deal with stress, shock and unease.

The first of these things would be trying to get my mind off of the situation, I can't really tell you what you should do, try and distract yourself for a little while with something you enjoy doing. With a distraction you can take your mind off the issue at hand, constantly worrying about outcomes and scenarios will have you over-worried.

Next, try and relax your body. Sometimes the body tends to be uneasy when stressful or fearful situations occur. Try drinking some tea, and wrapping up in a blanket, take time to think and analyze the situation.

The last step to calming down is friends and family, i can not stress how important it is that you talk to people when you don't feel right. Talking out your issues is the best way to have others relate to you, or for you to relate to others. Keeping a steady conversation going can tend to ease your mind and body even without doing both of the above things.

I'm very sorry to hear your friend is in the hospital, hope things work out. I myself have never had the opportunity for a friend to be hospitalized, most die before they reach the hospital. I hope all is well.

She's in the best place for care, and they have drugs for quickly stopping the vomiting, and lots of things they can do to lower her fever.

Don't assume the worst, hope for the best and pray. Work on a get well card and gift now to get your mind off of it :)

Take 1 or 2 5 mg of valium.

not rush to yahoo answers but rush to the hospital and get news from the doctor telling you whats wrong and if everything is gonna be alright.

Know she's in the best care possible at this point and whatever's wrong with her will be resolved.

All you can do is wait. Especially since his/her family might be more panicked than anyone else is right now.

you should like fall asleep for 7 hours

high fever and vomiting are usually not fatal...

breath. everything will be okay. your friend probably has a virus. it'll be alright