Hong Kong recorded record high temperatures in recent days while the Labour Department’s Work Heat Stress Warning remained at its lowest, yellow level, prompting criticism of the system.
Former Observatory director Lam Chiu-ying said using the Observatory’s Hong Kong Heat Index as the basis for the warning involved a technical error. His assessment has not been independently confirmed in the information available.
Lam said the alleged error was discovered only about three years later. The starting point and the date on which it was identified were not specified.
Former Observatory directors Chan Chi-ming and Lee Bo-ying have also questioned the use of the Observatory’s heat index as the warning standard. They called for the system to use black globe wet-bulb temperature, known as WBGT, data instead.
Lam said the episode showed that policymaking should follow science and give weight to a range of views. He warned that ignoring those principles could eventually lead to problems.
The Labour Department’s technical basis for using the Hong Kong Heat Index, the precise nature of the alleged error and its effect on warning levels remain unclear. It is also not known whether the department accepts the criticism or plans to review the warning standard.