STOP
Stop, insulate, eat and drink. Take shelter, ideally inside a bothy bag and, if you are with a group, get them to layer up and eat something while you assess the casualty. Make sure the injured person is insulated from the ground by sitting on a rucksack or similar and help them put on extra layers. Stay warm yourself.
ASSESS
Check CSMS (circulation, sensation, movement, strength) and range of movement. How does the ankle look? If it has swollen immediately, looks deformed, or if the casualty appears to have gone into shock, phone Mountain Rescue requesting emergency evacuation. If the casualty appears otherwise well and can walk four steps, treat it as a sprain but, depending on severity, consider adapting or ending the walk.
TREAT
Allow the casualty to…
