Industrial Relations Minister Grace Grace warned businesses had an obligation to protect their workers from heat-related illness under work health and safety laws.
"Working in the heat can not only be uncomfortable: it can be dangerous and even fatal," the minister said.
In 2020 a worker collapsed and died after picking fruit on a farm in high temperatures, and in 2021 a North Queensland worker died from multiple organ failure due to heat-related illness.
In both cases, the businesses involved were prosecuted and fined for failing to comply with health and safety duties.
"The solutions can be as simple as providing shade, avoiding outdoor work during the hottest part of the day, and ensuring inductions for new workers cover key safety measures," Ms Grace said.
The Bureau of Meteorology re-issued a severe weather warning on Wednesday for an area stretching from the Gulf Country to the southeast coast.
Maximum temperatures topping 40C are expected in Queensland's central and western regions, with little relief overnight as minimums simmer in the high 20's.
Queensland's east will be hit with maximums in the mid to high 30's, with overnight minimum temperatures slightly cooler, around the mid 20's.
Heatwave conditions are expected to intensify and extend across most of the state.
The warning urged people to find a place to keep cool such as a home, library, community or shopping centre, close the blinds or curtains early to keep the heat out and use fans or air conditioners if possible.
6°C