Hong Kong’s outdoor workers could still lack adequate rest under the revamped heat stress warning system, a lawmaker and a construction industry representative have said, adding that work breaks triggered by higher alerts are not protected by law.The response followed the Labour Department’s announcement on Thursday that it had updated the Heat Stress at Work Warning system to better safeguard outdoor workers, after the mechanism was criticised for the lack of higher-tier alerts during record-breaking temperatures earlier this month.Lawmaker Lam Chun-sing, chairman of the Federation of Hong Kong and Kowloon Labour Unions, said on Friday that the department should consider extending rest days to workers with moderate workloads under the system’s highest-level black warning, so that street cleaners could be covered.“Aside from modifying the triggering mechanism, the threshold requirements for the highest heat stress warning signal remain high,” he said.Lam cited that all non-essential outdoor workers were required to stop working regardless of their workload when either the No 9 or 10 typhoon warning was issued.The number of days a year when the highest heat stress warnings were active could be even less than the days when the highest typhoon signals were in effect, he said.