Maybe this is a stupid question but being from Europe and having worked as a paramedic I just have to ask... aren't there any emergency services or ambulances available to rush your son to the ER? I know over here, in cities they are sporting response-times of 5 to 10 minutes to your doorstep, 24/7.
Yes, of course, but see reply down-thread. I was called by the school, so the school nurse had made an assessment that the situation was non-critical. Since ambulances are a limited resource, why take it away from someone who could be in critical condition?