Hong Kong considers lowering heat-stress warning thresholds amid criticism
Commissioner for Labour Sam Hui says thresholds could be adjusted after the heat-stress warning was not upgraded during hottest day on record
Commissioner for Labour Sam Hui Chark-shum said on Tuesday that the warning system was currently more responsive to “muggy weather” than to conditions involving purely high temperatures and strong solar radiation, but the government would seek to improve its sensitivity during periods of extreme heat.
Hui said the heat stress at work warning system took into account factors such as air temperature, humidity, wind speed and solar radiation, but that their weighting had been “localised” to suit Hong Kong’s climate.
“In Hong Kong, the heat stress does not always track actual temperature change. When the humidity is high and the wind speed is slow, our cooling efficiency will drop sharply even if the temperature is not that high, and the associated health risk could be higher than in a well-ventilated open space with a higher temperature,” he said.
“Our system is more sensitive to this muggy situation, and the weighting of direct solar radiation is relatively smaller.”
The Labour Department came under criticism after its Heat Stress at Work Warning System remained at the lowest level while the city’s forecaster recorded a scorching 36.9 degrees Celsius (103 Fahrenheit) on Sunday afternoon – the highest temperature since records began in 1884.