We haven't had many issues with injury and only one heart attack scare. While we don't have super professional medical care on site we do all have phones and help is only a small distance away. Rescue is actually quite responsive in Thailand, this surprised me on that day where we had the heart attack scare. The response was extremely quick and professional.
On big events like the Ballbreaker we let rescue know where we are and what we are doing so that if we do need to call them they can get to us even faster. Thankfully, we don't often have to cash in on this though.
RE: Time is running out to book your spot with the Ballbreaker run