Hong Kong’s heat stress warnings fail to consider varying temperatures across city, experts and environmental group warn
- Greenpeace Hong Kong and experts urge city to revise warning system introduced to protect workers from heat stress, note readings just based on one location
- ‘We demand authorities prepare the best protection for workers before extreme heat approaches next year,’ group adds
Hong Kong should revise a warning system the government introduced three months ago to protect workers from heat stress, as it had failed to consider variations in temperatures across the city, an environmental group and experts have warned.
Greenpeace Hong Kong on Thursday said a study conducted last month showed results for the city’s heat index could drastically vary according to location, but noted the Observatory only issued warnings based on readings from its King’s Park Meteorological Station in Kowloon.
“The growing climate crisis is pushing temperatures up year after year. We demand authorities prepare the best protection for workers before extreme heat approaches next year,” said Tom Ng Hon-lam, a campaigner for the group.
The city issues an amber warning once the index hits 30, before upgrading to red or black if it reaches 32 or 34, respectively.
Depending on the signal issued and the intensity of their duties, labourers are advised to suspend work or rest for periods of 15 to 45 minutes.
The department had issued 47 amber warnings as of July 31, but has yet to send out a red or black signal.
Since 2014, the heat index has only reached levels that would have required a red warning on four occasions. No past readings have hit the threshold for a black signal.
But critics have complained about the sudden issuing and cancelling of warnings, leaving workers and employers confused over when to rest or return to their duties.
On July 5, an amber warning was issued at 2.20pm and cancelled an hour later. It then came back into effect about 10 minutes later.
The department in May published voluntary guidelines on heatstroke prevention as a reminder for employers and staff to take appropriate measures when working in hot weather or environments.
Ren Chao, an associate professor of applied climatology and climate design at the University of Hong Kong, said any guidance should take into consideration “differences in the microclimate within the same city”.
“The release of heatstroke prevention guidelines purely based on the meteorological data from the King’s Park Meteorological Station cannot properly represent the heat conditions of different districts in Hong Kong,” she said.
In a three-day survey, Greenpeace last month collected data from seven construction sites and recorded discrepancies of up to 8 degree Celsius (46.4 Fahrenheit) between the temperature readings taken.
Ignatius Yu Tak-sun, chairman of the Hong Kong Workers’ Health Centre, said the city’s heat index was “not an appropriate method to measure [labourers’] heat stress during work”.
Former Observatory director Shun Chi-ming earlier suggested authorities merge the warning system and the heat index to prevent any inconsistencies between the two.
Greenpeace on Thursday also recommended the government peg the system to other heat-related signals, such as the “very hot weather” warning, as well as offer real-time monitoring at construction sites and issue preliminary warnings to avoid sudden cancellations.
The Labour Department said employers were also responsible for assessing heat stress levels at the workplace and taking appropriate measures to prevent related illnesses among their staff.
The department added it had introduced a revised warning system on July 6 with the help of the Observatory to adjust the parameters of the warning system.
Deputy Commissioner for Labour Vincent Fung Hao-yin last month told a Legislative Council session that the department would look at possible improvements after the summer.
