As soon as you have identified the extent of the injury or illness, then it may be necessary to contact the emergency services. They can be contacted by dialling 999 or 112.
Activate the speaker function on the phone to aid communication with the ambulance service.
They will also require specific details about the location of the incident. It is imperative that you have the full details of where you are, particularly if the premises are large and have multi-floors or other buildings to consider.
Only dial 999 if it is necessary and consider other services such as Police and Fire, dependent on the incident.