A teenager who died in sweltering heat on a trip to Morocco with his classmates was prescribed medication for bed-wetting at the time of his death, an inquest has heard.
Samuel Boon, 17, collapsed as he took part in a trek in the north African country in July 2012.
The World Challenge trip was due to last 14 days and included a six-day trek to Amezmiz in the High Atlas foothills.
Samuel's family has demanded answers following his death, claiming he was left waiting for two hours on a roadside after collapsing, when a minibus rather than an ambulance arrived.
Giving evidence at the inquest at Bromley Civic Centre in south east London, Samuel's mother Karen Boon said her son had a repeat prescription for the drug DesmoMelt which he had taken with him to Morocco.
Users are warned against drinking fluids an hour before taking the drug and only drinking limited amounts up to eight hours afterwards, Mrs Boon added.
She said her son would still take the medication periodically as "reassurance" despite no longer struggling with the condition.
"The problem really was a thing of the past," she said.
"The nurse at the enuresis clinic said when boys hit puberty very often they see a great improvement around that time and that's exactly what happened."
She added: "I knew you had to be careful before you took the tablet - an hour before or eight hours after."
Mrs Boon insisted her son, who was 6ft 2in and weighed more than 20 stone, had been physically active ahead of the Morocco trip.
But she admitted Samuel's written application for the trip had not included details of his medication for bed-wetting.
She found three DesmoMelt tablets were missing when his belongings were recovered after his death, the court heard.
"If he took any he would have taken them in the hotel because he was sharing with two other people," Mrs Boon said.
Eleven pupils from the Business Academy in Bexley, south east London, went on the trip, and had raised funds to support the expedition.
They had been due to work on a rural project for seven days after the trek, but the trip was cut short after Samuel died.
At the time of his death, temperatures in the region were reported to have risen as high as 49C (120.2F).
Mrs Boon told the court that her son, who was classed as obese with a Body Mass Index (BMI) of 36, walked regularly before going to Morocco and often played golf with his father.
"He was up for going out with friends," she said.
"He walked to school every day, which was 20 minutes to half an hour each way, and he walked our dog most days."
"He was not a couch potato?" coroner Selina Lynch asked.
"No," Mrs Boon replied.
"We knew he was going to be walking five hours a day," she added.
"I didn't think that would be a problem with breaks."
Mrs Boon told the court that a presentation she attended from the trip's organisers had placed an emphasis on safety.
Organisers had claimed a satellite telephone, emergency beacons and a helicopter evacuation would be available in emergency situations, she said.
"I thought he was in a protective bubble," she said.
Before today's hearing, the teenager's father, Ken Boon, said in a statement: "Sam collapsed on the second day of the trek and had to wait for two hours by the roadside in extreme heat for evacuation, which came in the form of a minibus rather than an ambulance.
"Whilst the expedition leader and the school staff did everything they could on the ground to try to save him, they, along with our son, were badly let down and we hope the inquest will answer our questions as to why this happened."
Mrs Boon told the court her son, who was studying Maths and Physics A levels, was an "easy going, laid back young man" who had previously stayed away at V Festival with his friends in 2011.
The inquest is expected to last five days.
William Pemberton, Bexley Business Academy's head of sixth form, told the court that World Challenge insisted it would "pull out all the stops to ensure students were safe", including the use of satellite phones, emergency beacons and helicopter use.
"The big thing was the safety of students was paramount," he said.
Mr Pemberton said he was unaware that expedition leader Stephen Bates was leading his first trip to Morocco or that he had been recommended by assessors for an "easy lead" trek pending further youth work.
A World Challenge spokesman said: "Everyone at World Challenge was deeply saddened by Samuel Boon's death and our deepest condolences are with his family.
"We are providing all possible support to the coroner to help her determine the circumstances around Samuel's death."