It's known as "mango madness": the mysterious ailment that descends on the Top End as the build-up of humidity increases, blamed for driving up crime and dragging down morale.

And Matt Brearley, whose job it is to train tradespeople and labourers in the art of keeping cool, says it's no myth.

To investigate how bad the heat gets, Dr Brearley relies on a small ingestible pill that tracks workers' core body temperatures as they move through a hot working day.

He found the effects of prolonged heat exposure — when the temperature rests above a healthy window for too long — can be widespread.

"You can see that relationships with co-workers and family members, as well as recreational activities outside of work are often impacted," he said.

"We think all this feeds into this perceived mango madness."

A different kind of hangover

As well as age, fitness, and individual resilience to heat playing a factor, Dr Brearley found that born-and-bred Darwinians are less likely to succumb to severe heat stress.

Interactive heat-mapping technology shows the surface temperatures of a worksite. ( ABC Radio Darwin: Jesse Thompson )

"A new resident will probably not be as heat acclimatised as a resident with many wet seasons behind them," he said.

He warned that some people, especially interstate workers in heavy protective gear, can become dangerously oblivious to heat's long-term effects.

Sustained heat exposure can leave people with what's known as a heat hangover — suffering as if they've had a big night, without a drop of alcohol.

"Symptoms of headaches, nausea, lack of energy, lethargy, and lack of appetite manifest as a result of being exposed to heat beyond a person's capability," he said.

"It's almost universal that we've all suffered one at some stage and many workers are suffering them regularly."

A heat hangover can also stretch on for days if ignored, leading to periods of prolonged irritability and fatigue.

"We're seeing that the effects are not finished when you finish your work shift or when you finish mowing the lawn or playing sport," he said.

"They're long-lasting, and have a long-lasting effect on how people go about their business in the Top End."

Dr Brearley works with Power and Water to help employees keep cool on-site. ( ABC Radio Darwin: Jesse Thompson )

Beating the heat

Research recently published by Dr Brearley and his colleagues showed a marked increase in suicide and assault in the Top End's steamy wet season.

Part of the solution, he said "was recognising the seriousness of sustained exposure to heat".

Tips for beating the heat Jump in the pool, spa or bath tub for 20 minutes

Jump in the pool, spa or bath tub for 20 minutes Take a cool shower

Take a cool shower Keep a cold drink handy — especially if it has crushed ice

Keep a cold drink handy — especially if it has crushed ice Resist the urge to skip meals

Resist the urge to skip meals Gradually expose yourself to heat

The heat stress consultant also urged the Power and Water employees he worked with to realise they don't have to suffer through the high temperatures.

"The first thing we need to do is stop being so macho about living in the Top End," he said.

"We need to realise that feeling hot and uncomfortable doesn't have to come with the territory. Second, we need to treat it with evidence-based solutions."