• Charles Sturt University research investigates how the changing climate is impacting people’s ability to work outdoors
• At-risk groups in Australia include miners, athletes, farm workers, and defence personnel
• Findings can be applied to inform adaptation strategies on how to beat the heat to continue outdoor work

When working outdoors have you increasingly thought ‘it’s too hot for this’? Charles Sturt University researchers have evidence that you might be right.

Gulbali Institute for Agriculture, Water and Environment researcher and Associate Professor in Geospatial Science Dr Andrew Hall has published research on how changes in climate might impact outdoor physical activity.

The study reveals predicted changes in climate might impact people’s ability to work outdoors in Australia at different times of the year.

Using wet bulb globe temperature, which is used to assess physical activity limits by combining key meteorological data and a military heat categorisation system, researchers assessed different climate scenarios across Australia.

“It was found that in the next 20 to 60 years, physical activity will become more restricted across a larger area of Australia,” Dr Hall said.

“As the climate warms, we might have to implement new ways of managing physical outdoor work across much of the continent.”

Dr Hall suggested taking longer breaks across longer periods of the day and requiring breaks during more months of the year as solutions.

The research is important, according to Dr Hall, as a warmer climate reduces the effectiveness of the human body’s cooling mechanisms.

Unchecked heat exposure combined with physical activity can lead to incapacitating heat illnesses and, in the most serious of cases, life-threatening heatstroke.

“Developing a greater understanding of the risks associated with working in increasingly hotter weather will help communities and industries to adapt,” he said.

“At-risk groups in Australia include miners, athletes, farm workers and defence personnel.

“The research shows there’s a need for greater understanding about human physical activity limits and the risk exposure to heat-related injury, above the current highest heat categories used to inform outdoor work practices, to prepare for a warmer climate.”

An international standard heat measure, the wet bulb globe temperature (WBGT) that was developed by the United States military in the 1970s, is commonly used to determine heat categories that recommends limits on physical activity.

Dr Hall said his research has shown that the rate of increase in WBGT over the next 50 years will move many areas of Australia into more restrictive categories.

For example, the modelling indicates that Longreach and Townsville, under average daytime January temperatures with clear conditions and a 10 km/h windspeed, will move from Heat Category 2 under recent climate conditions to Heat Category 3 by 2050.

Moderate physical activity (such as brisk walking or gardening), which under Category 2 conditions can continue for 150 minutes in any four-hour period with minimal risk of heat injury, will, under Category 3, be reduced to 100 minutes.

Dr Hall said this research assists the focus of the Gulbali Institute, which was launched in Wagga Wagga on Friday 25 March, of solving core challenges for climate change resilience and adaption.