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Letters

Feel strongly about these letters, or any other aspects of the news? Share your views by emailing us your Letter to the Editor at letters@scmp.com or filling in this Google form. Submissions should not exceed 400 words.
Despite record-breaking temperatures in Hong Kong, the Labour Department’s Heat Stress at Work Warning system remained at the lowest level of amber on August 9.
The reason for this absurdity is the use of the Hong Kong Heat Index (HKHI) in determining the threshold for issuing the three levels of warning – amber at 30, red at 32 and black at 34.
HKHI was developed through research by the Hong Kong Observatory and Chinese University as an indicator of the risk of emergency hospital admission for the public in Hong Kong. The Wet Bulb Globe Temperature (WBGT), on the other hand, is widely used around the world to assess heat exposure at work, including by international standard ISO 7243.
Both HKHI and WBGT utilise the same three primary measurements: natural wet-bulb temperature (Tnw), globe thermometer temperature (Tg) and dry-bulb or ordinary air temperature (Ta). Following physical principles, natural wet-bulb temperature is always lower than air temperature, except when relative humidity reaches 100 per cent. The globe thermometer, which measures solar radiation, almost always shows a higher reading than air temperature for outdoor environments in the daytime.
HKHI is calculated using the weightings of 0.8, 0.05 and 0.1 for Tnw, Tg and Ta, while the corresponding weightings for WBGT are 0.7, 0.2 and 0.1. Mathematically, an HKHI reading will tend to be lower than a corresponding WBGT reading.
Three former directors of the Observatory have openly objected to the use of HKHI in assessing heat stress among outdoor workers, as the original research focused on health outcomes among the general public.
Many recommend using WBGT instead. Some countries using WBGT as the heat indicator for workers have set 28 degrees Celsius as the starting point for preventive action.
The Labour Department should take heed.
Dr Ignatius Yu, chairman, Hong Kong Workers’ Health Centre
Fire inquiry documents should be more accessible
The Independent Committee on the Wang Fuk Court fire has published a large body of material – witness statements, hearing transcripts, expert reports and photographs. Its website orders them by the sequence of the committee’s work, not the tasks outlined in its terms of reference. Journalists and members of the public seeking evidence on sprinkler failure or tender collusion must wade through page after page.
To test whether the material could be made navigable, we used artificial intelligence (AI) tools: a web crawler collected every document from the site, and large language models read, summarised and tagged each against the tasks outlined in the terms of reference.
The results are striking: 243 documents, 6,377 pages, 1.9 million words and roughly 1,800 meaningful photographs and diagrams.
Yet the material is unevenly distributed: supervision and responsibilities come up in 192 documents, adequacy of laws in 77 documents and collusion – what residents most want explained – in 99 documents.
Nor is that all. In asking AI to read every document, we found evidence of collusion (such as oral subcontracts) in documents that never use the word and are invisible to keyword search. Every document is public, but the questions people ask are the ones the archive makes hardest to answer.
To help readers answer them, we have built a free bilingual site (wangfukcourtfirereport.simonsays.hk). Each document has a page with a summary, key points and a link to the original PDF; an interactive map shows how the documents relate to each task; and full-text search spans all 243 documents.
We urge the independent committee to reconsider its approach and adopt new technologies to present its findings in a more accessible manner.
Wenyun Fu and Simon Wang, Kowloon Tong
Sound leadership is required for a US-Iran resolution
It’s about time that the United States and Iran settled matters with genuine intent. It’s like Tom and Jerry right now with their announcements. Real leaders would not allow any of this, nor threaten others who have an equal right to life.
We shouldn’t be teaching our children that war is a necessary course of action. Good leaders would be able to resolve crises, but where are they?
Rishi Teckchandani, Mid-Levels


Hong Kong must prepare for the impact of heat-related work stoppages

Hong Kong open to classifying heatstroke as an occupational disease: labour chief

How to take care of your dog during Hong Kong’s summer heat and thunderstorms

In an era of extreme summers, it’s time to look beyond air conditioning

Hong Kong weather

Hong Kong mustn’t use the wrong index to gauge outdoor heat stress

Construction workers rest during extremely hot weather in To Kwa Wan on August 10. The Wet Bulb Globe Temperature reflects solar radiation more accurately than the Hong Kong Heat Index and should be used to assess heat stress for outdoor workers. Photo: Sam Tsang

Practical ways to protect workers and projects in very hot weather

A construction worker works during extremely hot weather in To Kwa Wan on August 10. To keep outdoor workers safe and productive, measures like phased work schedules and portable cooling stations could help. Photo: Sam Tsang

Why is Hong Kong’s heat-stress warning system for outdoor workers in the hot seat?

The record-breaking heat sparked controversy over the Labour Department’s Heat Stress at Work Warning system. Photo: Handout

Labourers work in extreme heat at a construction site in Central. Photo: Sam Tsang

All three former Observatory directors have urged the Labour Department to adopt WBGT, which gives greater weight to solar radiation, and revise its Heat Stress at Work Warning system accordingly. Photo: Sam Tsang

Climate change demands stronger worker protections in Hong Kong

People wait to cross the road in Tsim Sha Tsui during heavy rain on July 16. For delivery workers and part-timers, income is tied directly to hours worked and work suspensions during extreme weather can mean immediate financial hardship. Photo: Jelly Tse

Opinion

Readers discuss how to better assess heat exposure at work, the accessibility of the Wang Fuk Court fire inquiry documents, and the US-Iran war


Readers discuss how to better assess heat exposure at work, the accessibility of the Wang Fuk Court fire inquiry documents, and the US-Iran war.


Extreme weather

Hong Kong Observatory

Hong Kong workers and labour rights

Hong Kong

.css-1c6uqr6{color:inherit;font-weight:inherit;font-size:inherit;font-family:inherit;line-height:inherit;overflow-wrap:break-word;}Readers discuss how to better assess heat exposure at work, the accessibility of the Wang Fuk Court fire inquiry documents, and the US-Iran war

Readers discuss how to better assess heat exposure at work, the accessibility of the Wang Fuk Court fire inquiry documents, and the US-Iran war