This is the moment when time really does matter. If the patient is having a heart attack a 20 minute wait for an ambulance can mean the difference between life and death.
Thankfully in Amber Valley a team of 15 trained volunteers are putting themselves in a position to help.
'First responders' are volunteers trained in first aid who give up their free time to be on hand in case of an emergency.
They are on call for cardiac arrests, people with breathing problems, heart or chest pains, and diabetes problems, and provide support to individuals in trouble while the ambulance is on its way.
In rural areas it can sometimes be as long as 30 minutes before paramedics are on the scene.
First responders are called out if they are within eight minutes of those in need.
Dave Roberts, a state registered paramedic set up the Amber Valley leg of the first responder scheme when both his parents became ill.
He said: "My mum had a heart condition and my dad had a cerebral problem. It concerned me that both my parents were ill and I personally would want someone there very quickly– that is really why I set it up.
"Our motto is 'When Time Matters' and when someone is in cardiac arrest, time does matter."
Mr Roberts now co-ordinates the volunteers in the Amber Valley area. These members manage the impressive task of covering the 104 square miles in Amber Valley – which is why the team is currently looking to recruit more volunteers.
Keith Smith, from Nether Heage, was already a Red Cross first aider at his work, LB Plastics, when he decided to sign up. He heard about the scheme through a contact at the local Neighbourhood Watch group.
During his 18 months in the role he's been called out to more than 30 emergencies.
He said: "It gives you extra skills and is great experience for handling people. When you are a first responder you are out their helping people with major injuries dealing with life and death situations."
He explained that first responders are supported through the whole process which begins with a through 36 hour course from East Midlands Ambulance Service which equips volunteers with all the knowledge they need to save a life.
As well as that, volunteers have free top up training once a month and are provided with all the correct kit for handling emergencies including equipment such as defibrillators, oxygen cylinders, and resuscitation masks.
The volunteer can do a minimum for 12 hours a month which involves being within reach of a phone and ready for action during an agreed flexible period. If there is a problem the ambulance service will contact the first responder and if they are close enough they will be sent out to assist.
The first few times for a volunteer can be daunting but they are supported every step of the way and to start with are sent out with an experienced responder.
Wayne Lenton, from Duffield, has been volunteering for nearly two years.
He said: "It is just great knowing that you can do something for somebody if they are in distress."
In order to volunteer you need to be fit and healthy, willing to learn, over 18 years old, hold a current driving licence and have access to a vehicle.
Anyone who would like to get involved can visit www.avrs.org or call Mr Roberts on 07768 694793.