Greenpeace and worker concern groups suggest following international guidelines for Heat Stress at Work Warning

Greenpeace said on Thursday that there were various loopholes in the guidelines to prevent workers from heatstroke and suggested the government utilize the international standard instead. 

Despite the Labor Department's (LD) revision of the Prevention of Heat Stroke at Work, there were still workers suspected of dying from heatstroke recently.

Greenpeace campaigner Tom Ng Hon-lam said the LD's guidelines only take the weather data recorded by the King's Park Meteorological Station as references, but each district has different heat levels.

He added that after Greenpeace visited different districts to measure the Wet Bulb Globe Temperature (WBGT), an international standard for measuring the effect of heat on the human body, there were discrepancies in different locations and proving that workers face different heat levels.

Ng suggested the government monitor the WBGT at different work sites to safeguard the workers' safety.

Wet Bulb Globe Temperature (WBGT) measures the heat stress in direct sunlight, which considers the temperature, humidity, wind speed, sun angle, and cloud cover. It differs from the heat index, which considers temperature and humidity and is calculated for shady areas.

Ignatius Yu Tak-sun, the chairman of the Hong Kong Workers' Hearth Centre, stated that the Hong Kong Heat Index does not account for the factor of getting hit by direct sunlight, and it is only useful for safeguarding the members of the public but not protecting the workers working in harsh conditions.

He also pointed out that the threshold for triggering the Red and Black "Heat Stress at Work Warning" was too high, and the warning signals will be hoisted and canceled based on the fluctuations of the Heat Index. 

Yu suggested to the LD to hoist it alongside the Very Hot Weather Warning from the Observatory.