For emergencies starting outside of medical care, a key component of providing proper care is to summon the emergency medical services (usually an ambulance), by calling for help using the appropriate local emergency telephone number, such as 999, 911, 111, 112 or 000.
To prevent the delay of life-saving aid from bystanders, many states of the USA have "Good Samaritan laws" which protect civilian responders who choose to assist in an emergency.