Amid extreme heat in Hong Kong with urban temperatures reaching 35.4 degrees Celsius and record-breaking highs recorded, the Labour Department has only issued a yellow work heat warning, drawing scrutiny over the alert system that has never triggered red or black warnings since its May 2023 launch, as reported by Now News on August 10, 2026.
Outdoor workers continue to labor through the severe heat as temperatures break local records. The current work heat warning relies on the Observatory’s Heat Index, which factors in temperature, humidity, and emergency room admission data while placing an 80 percent weighting on natural wet-bulb temperature measures like humidity and wind speed, according to the Labour Department.
Evaluating the Labour Department Heat Index and Warning Criteria
Under the existing guidelines for preventing heat stroke at work, red or black work heat warnings trigger mandatory stop-work requirements for extremely heavy physical labor outdoors. However, employers can bypass the shutdown if they provide sufficient heat-mitigation measures, limiting the requirement to extended rest periods instead.
Former Observatory Director Lin Chiu-ying criticized the current index. According to Lin Chiu-ying, the Hong Kong Heat Index is designed to measure health risks for the general indoor population and lacks a solar exposure factor, making it unsuitable as a foundation for work heat warnings. Lin Chiu-ying advocates adopting internationally recognized wet-bulb and globe temperature indices instead.
Did You Know? The Labour Department’s work heat warning system has remained at the yellow level and has never issued a red or black warning since the guidelines took effect in May 2023.
Worker Advocacy and Government Review Plans
The Rights on Industrial Accidents Association has called for multi-track metrics to speed up warning issuance. According to Association General Secretary Siu Chin-man, authorities could implement a dual-track or multi-track system that retains the Labour Department index alongside a wet-bulb and globe temperature index, or a simpler temperature threshold such as a yellow warning triggered at 36 degrees Celsius.
Siu Chin-man also noted that obtaining workers’ compensation for heat stroke remains difficult, particularly in death cases that are frequently attributed to heart conditions, pointing to a need for a broader review of the compensation framework.
In response to the mounting criticism, Deputy Secretary for Labour and Welfare Ho Kai-ming stated that the government will review the mechanism. According to Ho Kai-ming, the Labour Department is working alongside government departments including the Observatory to reduce occupational safety risks for workers and will continue consulting professional departments to review the existing framework. Ho Kai-ming also acknowledged that cardiovascular disease claims remain difficult to verify as work-related injuries while affirming ongoing attention to worker health.
Frequently Asked Questions
What factors does the Labour Department currently use to issue work heat warnings?
The Labour Department references temperature, humidity, and emergency room admission data through the Observatory’s Heat Index, with an 80 percent emphasis on natural wet-bulb temperature factors.
What changes do critics suggest for the warning system?
Former Observatory Director Lin Chiu-ying suggests adopting international wet-bulb and globe temperature indices, while the Rights on Industrial Accidents Association proposes a multi-track system incorporating temperature thresholds like 36 degrees Celsius.
What are the employer obligations under red or black work heat warnings?
Employers must suspend extreme physical outdoor labor unless they implement adequate heat-mitigation measures, in which case they are only advised to extend rest breaks.
How do workers view heat stroke compensation claims?
The Rights on Industrial Accidents Association highlights that securing compensation for heat stroke is challenging, especially in fatalities often categorized as heart issues.
What has the government announced regarding the warning system?
Deputy Secretary for Labour and Welfare Ho Kai-ming stated that the administration will collaborate with the Observatory and other departments to review the current mechanism and protect worker safety.
How will outdoor workers be affected if authorities adopt international wet-bulb and globe temperature indices?
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