Seven teenage boys have been airlifted to safety by a police helicopter after getting lost on Dartmoor, police said.
The 14-year-olds were practicing for the annual Ten Tors trek across the national park when they became disorientated in low cloud on Sunday afternoon, Devon and Cornwall Police said.
The boys, from a school in Wiltshire, called police shortly after 4.30pm and were later found by the police helicopter near Great Kneeset in the north west of the remote Devon upland area.
"The boys, who were overdue in meeting up with their teachers, realised that they needed assistance and sensibly stopped walking in the worsening conditions," he said.
"The helicopter crew searched the moor in the area of Hangingstone Hill and located the boys safe and well near Great Kneeset.
"As the conditions were deteriorating fast the helicopter lifted the boys and their kit from the moor, making two flights to and from Okehampton military camp, where they were reunited with their teachers.
"With the annual Ten Tors event approaching, this is a timely reminder that conditions on the moor can change very quickly.
"It is important that any walkers take appropriate precautions with regard to the kit they are carrying and ensuring their route card is left with a responsible person. In the event of getting lost, disorientated or injured, always remain together as a group."
The Ten Tors Challenge, which has been running for more than 50 years, is organised by the Army and takes place each May. It involves teams of 14-to-20-year-olds enduring a two-day hike of up to 55 miles (88km) across Dartmoor.
In March 2007 Charlotte Shaw, 14, drowned after falling into a swollen river in March 2007 while hiking during severe weather conditions in preparation for the annual expedition. She was among 11 pupils from Edgehill College (now Kingsley School), in Bideford, north Devon, taking part in the challenge.