The 26-year-old Middlesex University student was 90 minutes from Chicago when the call went out for a doctor or nurse on his plane.
Dominic said: ‘I thought "I'm not registered yet" but I stood up and told staff I was a nursing student and they said ‘you're the only one who's come forward'.
‘They took me to the back of the plane where there was a guy who was having real difficulty breathing. He had an asthma inhaler in his hand. I think they thought he was having an asthma attack but his lips were very swollen. I have seen anaphylactic shock before and knew that was what I was looking at so it was a case of trying to think logically and knowing if he was that allergic he would have an Epipen.
‘I'd been on a plane for about seven hours but I was trying to think on my feet. So I got the stewardess to look through his hand luggage and there was an Epipen, which I administered.
‘I'm a cub leader and one of our kids has an egg allergy but he also carries an inhaler as well, it can seem very similar at the beginning I've been told.
‘The week before I left I had my emergency lifesaving training. The instructor said ‘you never know where you are going to use this, on a plane, on a train ...' so he jinxed me!'