When I was at school the girls wouldn't play hockey if the pitch was frozen they would have to practice gym indoors, still wearing their navy blue knickers of course.
In the NHL (National Hockey League) of Canada and the USA there are lots of minor injuries in the somewhat overly aggressive game; however, I doubt that there is an ambulance parked outside every arena in case of a major incident. All of the hockey arenas are located in major cities, and a call to 911 would quickly make an ambulance appear.