Labour commissioner questions heat warning system

Labour Commissioner Sam Hui and his team have raised concerns about the sensitivity of Hong Kong's heat stress warning system. Despite record-high temperatures, the system remained at the lowest amber level on Sunday, sparking a review of its current mechanism. Hui acknowledged that his department questioned the system's response while monitoring the weekend's temperature fluctuations.

He noted that on Saturday and Monday, the heat stress warning level did not escalate, leaving them with many questions. The Labour Department is working with the Observatory to improve the system, which is currently based on the Observatory's heat-stress indicators designed for Hong Kong's unique humidity and hot climate. These indicators are highly sensitive to humidity but assign less weight to thermal radiation from direct sunlight compared to other international systems.

Hui suggested that they may need to adjust the activation threshold for higher-level warnings under extremely high temperatures to better reflect the overall severity of heat conditions. The department is also considering rebalancing the weighting of indicators to more accurately capture severe conditions during extreme events while preserving the original framework for Hong Kong's climate.

The amber alert, indicating high heat stress in certain work environments, has been in effect since Tuesday morning. The Observatory predicts maximum temperatures of 33 to 34 degrees Celsius in urban areas over the coming days, potentially reaching higher levels in the New Territories due to a southwesterly airstream.