Air Training Corps Cadets from Sheffield raised cash for charity by completing a 100-mile march in searing heat in the Netherlands.
They represented Britain in the Vierdaagse annual event in Nijmegen, which has taken place since 1909.
They marched alongside 45,000 others at the event, crossing four borders and marching a total of 163 kilometres.
Flight Lieutenant Andy Williams, South and West Yorkshire air cadets manager, said: “The first day was very hot, with temperatures of more than 32°C.
“Some of the adult teams really struggled, dropping out due to the heat.
“It’s a testament to the efforts of the cadets that they put in all this effort and were successful in the end.”
He said the selection process was tough, with 60 cadets starting training just after Christmas.
After five training marches, a team of 24 took part in a two-day event at RAF Cosford, from which 10 cadets were selected for Nijmegen.
Sheffield cadets Heather Williams, Will Haythorne, Jack Barraclough, Tom Williams, James Cooper and Tayla Shelley took part, along with Rotherham’s Louis Webb and Nick Bramall, of Bawtry.
They raised money for Cardiac Risk in the Young following the sudden deaths of Sheffield High School pupil Alex Reid in June 2012 and air cadet Michael Kentzer, who died in December 2011.
Tayla, a member of 366 Squadron of the Air Training Corps, and a friend of Alex, said the memory of Alex and Michael were fresh in the minds of the cadets.
She said: “We trained hard, trading our weekends for camouflage and blisters – something not all teenagers would consider spending their summers doing.”