A guest at a glittering Southampton Hospital benefit on Saturday night wound up in the hospital instead. The socialite was seen swooning in the heat, and, after hitting the deck, the brave dame initially refused medical attention, spies said. Despite her protests, an ambulance was called, whisking her off to the ER — which was, appropriately, moments from the party’s tony tent. “The benefit raised money for the hospital’s department of emergency medicine, so I guess they put the money to good use,” quipped an attendee at the bash, which brought in nearly $2 million. Guests included Peter Brant and Stephanie Seymour, Chuck Scarborough, Debbie Bancroft, Audrey and Martin Gruss. The Alex Donner Orchestra provided tunes at the shindig.