Fern Berkley, a student at Scarborough Sixth Form College, was chosen from over 300 cadets to compete in the International (St John) Cadet Competition in South Africa at the beginning of January.
She took part in a demanding national selection process which included an interview, presentation and first aid scenario and was chosen to be part of a team of five representing England and Northern Ireland.
Fern joined the cadets at the age of eight and says the organisation had helped and encouraged her to pursue medicine as a career.
On the competition in South Africa, as part of the England and NI team, Fern had to compete in realistic first aid scenarios including saving a drowned child, helping a cyclist with a suspected heart attack and supporting someone who had fallen from a roof.
Competing with teams of cadets from other countries, the teams were marked on the treatment they administered, its effectiveness and the phone calls they made to the emergency services.
Fern found the final scenario the most challenging as this involved dealing with ten casualties who had been involved in a serious car accident.
On the day of competition, temperatures hit 42 degrees and as team leader Fern was responsible for prioritising the wounded and allocating tasks to her team.
Overall the England and NI team won a silver and bronze award, and Fern additionally won a silver individual award for her role as a Drill Sergeant, commanding a squad from the South African army.
She said: "It was incredible, it was something I'll remember forever."
The trip was also an opportunity for the cadets to learn more about different cultures. All of the participants shared gifts from their countries with England and Northern Ireland taking seaside rock, royal family masks and Yorkshire Tea.
They also went on safari and worked on a school community project by helping to paint the school and donating books to the children and managed to squeeze in some sightseeing and canoeing too.
Fern said: "The scenery was beautiful and visiting the school was a really eye opening experience."
Fern, who is in Lower Sixth at Scarborough Sixth Form, is taking A Levels in Biology, Chemistry and Maths, is planning on studying Medicine at university following college and the judges commented that her performance in the competition suggests that she will make an excellent doctor.