Objectives: (1) To investigate workers' perceptions and behavioural responses towards extreme heat exposure in South Australia in the context of climate change, (2) To provide baseline information for developing current heat prevention policies and strategies.

Methods: A cross-sectional questionnaire survey was conducted among those working outdoors or indoors close to heat sources without air conditioning in the following industries: "agriculture, fishing and forestry", "construction", "electricity, gas and water", and "mining" in 2012, Adelaide, SA. Bivariate and multivariate survey logistic regression analyses were conducted using a stepwise backwards model to identify the factors associated with workers' perceptions of heat exposure.

Results: A total of 1,471 copies of questionnaires were distributed and 749 completed questionnaires were collected, with a response rate of 50.9%. Overall, about 51.2% of participants were moderately or very much concerned about the risk of heat illness at work during very hot weather. Following factors were found associated with workers' concerns over heat exposure, including age ≧24 years, physically demanding (very much), the use of personal protective equipment, and heat-related illness and injury history. A majority (68.8%) of participants were willing to adjust their current work habits to deal with the impact of possible increasing extremely hot weather.

Conclusions: Given Australia's existing thermal environments and predicted increasingly hot summers due to climate change, there was a misalignment of perceived occupational health risk. With weather projections, there is a need to develop specific and clear enforceable heat regulations to ensure the implementation and compliance of heat policies.