I know this may sound grim (given the context of the thread) but can I suggest another useful tool? In this case how to better call for an ambulance...you'd be amazed how garbled things can get, I know it should be obvious and the operators are very good but you'll find this helps. Very easy and useful acronym: L I O N E L
Location : "I'm at the junction of Smith St and Jones Road etc" Don't assume your mobile phone gives enough information
Incident : e.g. "There's been a road traffic accident etc"
Other Services needed : e.g. "We need the Police as well etc"
Number of casualties : "2 people are hurt etc"
Extent of injuries : "One is unconscious, the other has hurt their leg etc"
Location : Just in case you weren't clear
This way you can deliver the maximum amount of information, in a useful order, in the minimum time. I've had to use it a few times and it really settles the mind when you're otherwise not necessarily thinking straight.
Budge
p.s. It's also really useful to teach to kids.