This happens often (more then anyone wants to think about)
Dec 2001 our 9 month old DD had an allergic reaction to penicilin (she started it before the trip) and really swelled up. She could breath ok, but given her age and the recation we wanted her seen. We talked to our Ped on the phone and talked with the frount destk at the Poly (were we were staying)
They were very helpful. There are 2 good options. One is have a Dr. sent to your room. (more coslty) the other is go to a walk in clinic called Centra Care. Centra care sends a van to you (no cost, with car seat if needed.) The whole trip cost around 120 (with meds) Our insurnce didn't pay for it (I don't think they take insurance, but does give paper work if you want to sumit it later.)
The other option is to call your insurnce and see who they will pay for.
We ended up back at Centra care the next year. Ear infection. Happy to know they were there. The clinic was much less busy on a Sunday morning then a Monday afternoon.
Good to know they are there, and they took good care of us.