I think when its the first time something happens i freak - well depending on what it is.
DJ cutting his finger open on a bottle top i was like "meh" not like i could do much, first time he had a fit i screamed like banchee. the second time, dispite it being worse, i was clam and collected. DH the same.

DH also tends to panic more then me.

I think counting to 10 and realiseing your the adult and have to make things happen helps. Like with DJ - now when he has fits, no matter how long i know i need his meds to stop/control plus keep and eye on the time for length. he has them now and people dont pick up on it.

As for something like that - i'd freak the first time, but if on my own I'd suck it up and go to the hospital, try and be as calm as humanally possable *then* freak out once every thing had been explained to the people who needed to know.