A 33-year-old American tourist has died after taking a wrong turn while hiking the popular Larapinta Trail, west of Alice Springs in Central Australia.

Key points: Man 'ran off' from companion on descent

Man 'ran off' from companion on descent Body found three hours later, 750m from carpark

Body found three hours later, 750m from carpark Authorities warn against embarking on 16km Mount Sonder trek in the heat

Authorities warn against embarking on 16km Mount Sonder trek in the heat Route has steep, rocky incline with exposed landscape

The man, from California, set out to climb Mount Sonder about 8:30am on Wednesday and was found dead about 750 metres from a carpark near Redbank Gorge at 5:00pm.

Police said the man and a companion had climbed Mount Sonder, which is the fourth-highest peak in the Northern Territory, and were on the descent when they separated.

Duty Superintendent Rob Burgoyne told ABC Darwin: "It's about 1,300 metres tall and the actual walk that they undertook was about 16 kilometres there and back — so quite a hike."

Map Larapinta Trail map

The 40-year-old man he was walking with told police the 33-year-old ran off on their way back and appeared to have taken a wrong turn.

"They both descended the mountain, unfortunately it appears the deceased took a wrong turn at that stage," Duty Superintendent Burgoyne said.

"His partner made it back to the Redbank Gorge carpark and raised the alarm, but unfortunately the 33-year-old didn't arrive and his body was eventually located about 400 metres down the track where he'd turned the wrong way.

"It was about three hours from when he was last seen and when his body was found."

Police said investigations were ongoing but it was not believed there were any suspicious circumstances surrounding the death.

Temperatures reached 42C

The Bureau of Meteorology confirmed Alice Springs reached a top of 42 degrees Celsius on Wednesday, which Duty Superintendent Burgoyne said would have made trekking conditions difficult.

A section of the Larapinta Trail between Stanley Chasm and Jay Creek. ( ABC News: Steven Schubert )

"We do know he had water with him, but he did do a very foolish thing in that he apparently ran away from his companion after the descent," he said.

"It wouldn't be a terribly advisable thing to do in 40-degree heat, to actually sprint away."

Authorities warn against embarking on the long trek in the heat because it comes with a high risk of becoming dangerously dehydrated, Chris Day from Parks and Wildlife said.

"It's almost physically impossible to put back the fluids that you're going to lose as quickly as you're losing them, and unfortunately people become dehydrated very rapidly before even realising that it's even happening," Mr Day said.

"Unfortunately it is too late, quite often, once people realise they're in trouble."

The Mount Sonder walk is almost fully exposed to the sun and takes at least six hours. ( ABC News: Emily Butcher )

Mount Sonder, the final section of the 223-kilometre Larapinta Trail which the men were on, is a steep, rocky incline with an exposed landscape.

"Its a very exposed mountain walk," Mr Day said.

"There's no big shady trees and it's very rocky, so when you've got a hot day like we had (on Tuesday) we've got a lot of radiated heat coming back off the rocks.

"Obviously on days when temperatures are forecast to be in the 40s, we strongly advise against doing any longer walks."

Incident follows death of German tourists

The death comes 11 months after two elderly German tourists perished at Trephina Gorge, east of Alice Springs.

The German tourists died at Trephina Gorge, 85km south-east of Alice Springs. ( Northern Territory Government )

Mr Day said it appeared foreign tourists were not taking heed of warnings about the risks involved in the Larapinta trek, however acclimatising to the Territory's hot climate remained one of the main safety challenges.

"Quite often they would've not been in Australian conditions for very long and most possibly come from the northern hemisphere — effectively winter conditions — much cooler than what they're encountering here," Mr Day said.

Parks and Wildlife recommend trekkers allow six hours to do the walk. It also advised they leave at first light, take appropriate clothing, adequate water supplies and know their fitness level.

This is the second death in Central Australia within 10 days, with a man from Adelaide killed by lightning at King's Canyon on New Year's Day.

The US embassy said it was "aware of reports of the death of a US citizen in the Northern Territory".

"We are closely monitoring local authorities' investigation into the cause of death," an embassy spokesperson said.

The spokesperson said the embassy was ready to provide "all appropriate consular assistance", but would not add any further details about the tourist due to privacy considerations.

A report will be prepared for the coroner.