PICTURED: Boy, 9, who collapsed and died of a 'heat-related event' in front of his devastated family after they went on a hike through the 113F Arizona desert

A nine-year-old boy who died 'as a result of a heat-related medical event' after collapsing during a hike in the Arizona desert has been named by police.

Cortinez Logan was on a trail walk with his family at the South Mountain Park and Preserve near Phoenix as temperatures soared to 113F on Tuesday.

The Logan family set off in the early hours of the morning, but later in the afternoon Cortinez became overcome by the heat and began to go 'in and out of consciousness', officials said.

Phoenix Fire first responders were called to the area just before 3pm and the boy was airlifted to a nearby ambulance which took him to hospital, where he later died.

Detectives were on the scene at the park and attended the hospital to take over the investigation into his death, 12News reports.

Cortinez Logan went on a trail walk with his family at the South Mountain Park and Preserve 

Cortinez and his family had recently moved from Missouri to Phoenix.

First responders are reported to have administered CPR to the boy on the trail, but were unable to save him. 

Trails on South Mountain had been open on the day of the boy's death and the National Weather Service had not issued an extreme heat watch or warning, despite the triple figure temperatures.

Popular Phoenix trails usually close on days with excessive heat warnings.

Phoenix Fire Captain Todd Keller warned that it is vital for hikers to hydrate properly, and said they should always carry a cellphone and water.

'If you have someone who hasn't been properly hydrating, not drinking enough water, that heat can affect them within minutes,' Keller said.

'When you're halfway done with your water, you're halfway done with your hike. 

'If you start to feel any kind of dizziness or any lightheadedness, please stop, turn around, come back another day. Just because you don't make it to the summit of the mountain, doesn't mean it wasn't a successful hike.'

File image shows the Hidden Valley Mormom Trail in the South Mountain Park Preserve

Firefighters train for rescues in tough conditions such as extreme hot weather, but Keller said each call puts their team at risk.

'Our firefighters are the best-trained rescuers in the world. They know it's coming but the heat does affect them,' Keller said

'That's why we always say that if you're going to go up the mountain, you're putting yourself in danger and you're putting our rescuers in danger.'