Qld Industrial Relations Minister Cameron Dick said Queensland's workplace health and safety laws required employers to provide protection from the heat and sun to employees who work outside.

"Workers also have an obligation to comply with employer instructions and take appropriate precautions to avoid heat stress," Mr Dick said.

"Staff should be provided with personal protective equipment including wide brim hats, long-sleeved collared shirts, long pants, sunglasses and sunscreen to ensure they do not put themselves at risk."

Mr Dick said workers were most at risk during heat waves when temperatures soared above the average for three or more days and humidity was high.

"Extreme heat conditions can lead to heat-related health problems such as cramps, exhaustion, heat stroke, and fainting," he said.

"There is no set temperature at which work should be called off, however, employers should weigh up all factors such as heat, humidity, the nature of the work, water intake, breezes, protective gear, condition of workers and hours of work.

"Working smart and working cool can save lives in our hot summer climate."

Those most at risk of heat-related illness and skin cancer are:

• fair-skinned people and those not acclimatised to the Queensland climate
• workers exposed to direct sunlight between 10am and 2pm
• workers exposed to water, construction materials, polished aluminium and glass (common reflectors)
• workers carrying out strenuous tasks or sustained long work periods
• workers who are exposed to additional heat from machinery
• workers in northern parts of Queensland.

Factors that may contribute to heat-related problems at work include:

• inadequate cooling off or rest periods and insufficient water consumption
• climatic conditions (low air movement, high humidity, high temperature)
• inappropriate clothing
• those that may cause dehydration such as poor diet, vomiting, diarrhoea or alcohol and caffeine consumption
• individual medical conditions such as heart problems, diabetes and hypertension
• individual medication that may affect the body's temperature regulation
• age, general physical fitness and weight.

To help avoid heat-related illness in the workplace:

• provide access to shelter such as sheds, caravans, tents, windbreaks or portable shade canopies. In some situations, vehicles or public facilities may provide appropriate short-term shelter
• reorganise outdoor work if possible so that workers carry out alternative tasks, or work in shade, when the sun is most intense
• drink 150-200mm of cool fluids every 15 to 20 minutes, rather than one litre every now and again
• choose water or a sports drink rather than tea, coffee or milk
• if you become dehydrated, do not recommence work until you are fully rehydrated
• automate and mechanise tasks
• insulate or shield workers from hot surfaces and plant
• use ventilation and air-conditioning
• introduce humidity-reducing methods, for example, install a dehumidifier.

For more information on protecting your workers this summer, visit www.worksafe.qld.gov.au or call the WHS Infoline on 1300 369 915.