This weekend was one fuelled by football fever, with eyes firmly glued to TV screens as the Euro's finally kicked off a year later than originally scheduled.

But on Saturday - just two days into the tournament - there was shift in atmosphere, as attention turned away from the glorious game.

After Danish midfielder Christian Eriksen suffered what we now know to be cardiac arrest in the 42nd minute, an outpouring of social media activity swept the continent, with many sharing information on how to perform CPR on adults, children and infants and - if necessary - how to use a defibrillator.

Herts Advertiser: Defibrillators are used to shock the heart of someone who is in cardiac arrestDefibrillators are used to shock the heart of someone who is in cardiac arrest (Image: Maya Derrick)

A defibrillator is a device that gives a high energy electric shock to the heart of someone who is in cardiac arrest. Figures suggest that there are more than 10,000 defibrillators across the UK, saving countless lives each year.

Retired paramedic duty officer Rod Taylor worked for the East of England Ambulance Service for 39 years.

"What happened with Eriksen has put the importance of defibrillators centre stage," he said.

Herts Advertiser: Retired paramedic duty officer Rod TaylorRetired paramedic duty officer Rod Taylor (Image: Danny Loo)

"In our communities we have automated external defibrillators, or AEDs. Some are placed inside - in supermarkets for example - and many are outside in locked cabinets.

"In the event that someone needs access to a defibrillator, they would call 999. It doesn't have to be a heart attack, but could be a life-threatening situation is unfolding and the call handler has told them they need to gain access to a defibrillator."

He continued that the 999 operator will give the location of the nearest AED along with an access code to unlock the defibrillator. A voice command will tell the person using the AED what to do, step by step.

With many wary of using defibrillators, Rod runs familiarisation sessions so people feel more confident using one in case of an actual emergency.

He explained: "The AEDs are automated, not automatic, so you do have to press the button.

"However, if you put the pads on someone's chest and press the button to shock them, it will only deliver a shock to them if they are having a life-threatening arrhythmia. If the patient's heart is working fine, it won't shock them - which is something people don't realise."

He added that people are far better off trying to use a defibrillator than not having one around and standing waiting for an ambulance.

Reassuring their ease of use, he demonstrated that an AED - which only weighs around five or six pounds and costs £1,500 - could be the difference between life and death.

"They are important to have in the community as you are engaging the public," he said. "It involves the public and gives them the opportunity to help their fellow citizens in the event of a medical emergency. It's far better to attempt to use the device and help someone than not."

Echoing Rod's sentiments, Lorna Hayes, head of community response at the East of England Ambulance Service, said: “The quick actions of everyone involved in treating Christian Eriksen on Saturday showed how important it is to learn lifesaving skills and I hope that it will act as a catalyst for more people to undergo training.

“Early intervention by CPR and the use of a defibrillator is vital in what is known as the chain of survival and substantially increases a patient’s chance of a positive outcome.

“If you come across someone having a cardiac arrest, please call 999 straight away and we will provide you with advice on how to do basic life support, and locate the closest defibrillator, providing you with guidance on how to use it.”

Most publicly-accessible defibrillators are available on The National Defibrillator Database's interactive map. In an emergency, always call 999.