Hong Kong’s Labour Department will revamp the city’s heat stress warning system, its chief has said, after a former weather official called the mechanism “decorative” for issuing only the lowest alert during record-breaking heat. Hui said he and his colleagues were puzzled when recent high temperatures failed to trigger a higher alert under the Labour Department’s Heat Stress at Work warning system. Despite the heat, the Labour Department’s heat stress warning system remained at its lowest “amber” level over the weekend, prompting former Observatory chief Lam Chiu-ying to criticise the mechanism as “baffling” and “decorative.” ‘Hot and humid’The warning system consists of amber, red and black alerts and recommends different rest arrangements for employees working outdoors or without air conditioning. The system recommends rest arrangements depending on the type of work and the heat warning in force.