Heat strain a threat to workers even in cooler periods: Study

Findings suggest heat-related injury is a persistent risk not tied only to the weather

- Shabana Begum

A 22-year-old indoor construction worker's core body temperature exceeded 38 deg C during the second half of his work shift and his heart rate remained elevated.

The acceptable core temperature, or the temperature of a person's internal organs, is about 37 deg C. At one point, his heat strain index reached a high level of eight out of 10.

These findings might not be surprising for an outdoor worker toiling in a heatwave, but the 22-year-old was working underground in a tunnel during a cooler period in December 2022, when the northwest monsoon was bringing rain and overcast skies.

A few construction workers may be working harder during cooler periods, crossing occupational thermal limits, researchers from the National University of Singapore (NUS) found, after profiling the heat strain risk of about 160 construction workers here during the hotter and cooler months of 2022.

Their findings suggest that heat-related injury is a persistent risk here that is not necessarily tied only to the weather, and that employers and workers should be aware of it at all times of the year, even in the cooler months.

The worker also worked through his lunch period, taking a break only afterwards, noted Associate Professor Jason Lee, director of the Heat Resilience and Performance Centre at the NUS Yong Loo Lin School of Medicine.

"Our message is for (construction companies and workers) to be vigilant at all times when it comes to exertional work," said Prof Lee, who also leads Project HeatSafe, an NUS-based programme that has been finding out how rising temperatures affect the health and productivity of people in Southeast Asia.