"Extremely hot days can be dangerous to workers, with risks including slips and falls from fainting and heat fatigue, or losing control of tools due to sweaty hands," Mr Giandinoto said.
"Heat stress can lead to blackouts or loss of concentration that could be a risk to workers, their colleagues and even the public - especially where workers are in control of machinery.
"For outdoor workers, there is the added threat of exposure to UV radiation, which if not addressed could increase the risk of skin cancer."
Mr Giandinoto said workplace health and safety laws require employers to provide a safe working environment, which includes protection against risks associated with working in heat.
He urged workers to monitor their own working environment and the health of not only themselves, but also those around them in the workplace.
"This is the first really hot working week for many Victorians, so everyone needs to take extra care to make sure they look after themselves, their employees and their workmates.
"Simple things like rescheduling work to cooler parts of the day, making sure there is drinking water available, and providing outdoor workers with sunscreen and protective clothing can help to keep workers safe during this scorching heat."