The Hong Kong Observatory has issued a prolonged heat alert with the mercury forecast to hit 34 degrees Celsius in the city on Tuesday.

It will remain persistently very hot over the next couple of days, with cloudier conditions and a few showers expected in the latter part of this week, the forecaster said in an alert on Monday morning.

“Under the influence of an anticyclone aloft, the weather is generally fine over the coast of southern China,” said the observatory, which also issued a “very hot weather” warning at 6:45 am on Monday.

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A broad area of low pressure is bringing unsettled weather to the seas west of Luzon, it added.

The HKO advised people to avoid prolonged activities outdoors to prevent heat stroke.

“If engaged in outdoor work or activities, wear a wide-brimmed hat and light-colored, loose-fitting clothes. Stay in shaded areas as much as possible,” reads the bulletin.

It also asked people to drink plenty of water and avoid beverages containing caffeine or alcohol.

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With the heat stress at work warning in effect, the Labour Department reminded employers and employees to take appropriate measures to prevent heat stroke while working in hot weather or hot environments.

Cautioning that those working outdoors or in non-air-conditioned indoor environments face high levels of heat stress and are at a relatively higher risk of heat stroke, the department said employers should take necessary preventive and control measures, including rescheduling work periods, setting up shading covers, providing ventilation and heat dissipation equipment.