Mounties in Saskatchewan are crediting a high-tech drone for the rescue of a man who had walked away from his vehicle after a rollover crash and could not be found.

According to RCMP, the crash happened around 12:20 a.m. CST Thursday on Highway 5, about five kilometres east of St. Denis, Sask., which is about 35 kilometres east of Saskatoon.

Emergency crews were notified of the crash in a 911 call and police, ambulance and other rescue teams were dispatched.

However, when they arrived at the site of the roll over, there was no one in the vehicle.

"The examination of the scene indicated that at least one person had been in the vehicle and was injured," RCMP said.

A ground search was launched, but after rescuers scoured some 200 metres in all directions, there was still no sign of anyone.

RCMP then called in an air ambulance helicopter equipped with night-vision equipment and high-powered searchlights. The helicopter scanned an area about one kilometre around the crash site, again with no results.

Drone called in

Finally, about an hour into the search, RCMP called for their drone — an unmanned aerial vehicle with an infrared camera mounted on it.

The drone was at the scene, preparing to launch, when RCMP received a cellphone call from the injured man, a 25 year old.

"He indicated he was cold, did not know where he was and could give no directions to his location," RCMP said. He was only dressed in T-shirt and pants. He had lost his shoes in the crash.

RCMP said the temperature was near freezing at the time.

Police said they used the cellphone's signal to get a better idea of the man's location.

The new search area was a field more than two kilometres south of the rollover.

RCMP officers and rescue people, on the ground and in the helicopter, went to that location but again could not find the man.

Heat source spotted

Finally, at 3 a.m. the drone was launched and a small heat signature was detected.

Searchers were sent to that heat source, which was about 200 metres from the cellphone's last GPS ping. RCMP said the cellphone signal stopped transmitting after the last call.

"Fire and rescue members located the driver at this first location, curled up in a ball at the base of a tree next to snow bank," RCMP said. "He was unresponsive and was quickly brought out to the road."

He was taken to hospital in Saskatoon for treatment. RCMP said he was released Thursday afternoon.

RCMP said using their drone with the heat-sensing equipment was key in the rescue.

Drone made in Saskatoon

RCMP Cpl. Doug Green, who deployed the drone in the search, told CBC News the machine was built and designed by a Saskatoon company, Draganfly Innovations.

"It's a small little four-armed helicopter that has the capability of a camera or a FLIR [Forward Looking Infrared] or a low-light camera attachment that has a video link right back to the hand-held controller that I fly it with," Green explained. "I see exactly what the camera is looking at and I can control the camera up and down."

RCMP are trying out Saskatoon-made drones. A Dragan Flyer X4-ES was used to find an injured man who wandered away from a roll over crash. (Draganfly.com)

Green said the drone used a FLIR camera which detects heat from an object during Thursday morning's rescue.

He said that in most highway crashes, victims are found near to their vehicles or within about 200 metres.

In Thursday's case, Green said the man suffered a head injury and was disoriented.

"He just, instead of phoning right away, he wandered off and got lost in the dark," Green said, adding it was cold, the field had water in it and the wind was picking up. "He was wet and cold."

Green said the RCMP have been using the Dragan Flyer X4-ES for just over a year in a series of trials to determine how they might assist different elements of police work. Green was equipped with one for use in traffic analysis.

"We're still just trying out different platforms," he said, adding that five officers have obtained the necessary training and licences from aviation authorities to fly the devices.