The devastated family of a reservist who died during an assessment for the Territorial Army's SAS section on the hottest day of the year said he lost his life "in the pursuit of his dream".
Lance Corporal Craig Roberts died alongside another unnamed TA soldier during a military exercise in the Brecon Beacons on Saturday, as temperatures soared to 29.5C (85.1F). A third man remains in hospital.
According to sources, the trio were at the start of an assessment period in the selection process for the TA's section of the SAS, after completing a stint of training and preparation.
Mr Roberts, a teaching assistant at a school in London, was due to start work at the Department for Education next month on a prestigious training scheme.
In a statement issued through the Ministry of Defence, his father Kelvin Roberts said: "We are all devastated at the loss of our beloved Craig; this has left a massive hole in all our lives."
"We wholeheartedly supported Craig in his military endeavours and it gives us some comfort, though great sadness, that he died in the pursuit of his dream.
"Next month Craig was due to start a new post in the office of the Secretary of State for Education and we were all very proud of him."
Tributes have poured in for Mr Roberts, from Penrhyn Bay, near Llandudno, who worked as a teaching assistant at Trinity School in Lewisham, south-east London and had reportedly served with the TA for more than five years, including tours of Iraq and Afghanistan.
A spokesman from the school paid tribute to his "dedication, commitment and care" for young people. He said: "The staff and pupils of Trinity School, Lewisham, have been greatly saddened by the news of the tragic death of Craig Roberts. For the past two years Craig worked at Trinity as a teaching assistant and had become a much-loved member of the Trinity community."
The MoD has said there are no plans to change "routine exercises" in the rugged Brecon Beacons in light of the incident but the deaths have led to question marks around rigorous SAS training amid concerns by one unnamed army officer that the men were "marched to death" in extreme temperatures.