Despite evidence that a safe and healthy workforce is essential to construction project productivity, the resources and time committed to safety are often perceived as counterproductive. This study explores the multiple institutional logics underpinning the duality between safety and productivity in the construction industry. Specifically, it explores the tensions between safety and production through an institutional lens by untangling the institutional logics of processing safety in production. A theory of protection, production and reconciling logics is developed and refined through an in-depth case study of heat stress management in a mega-project in Australia. Ethnographic data were collected over a six-day working week on site, interpreted using institutional analysis and conceptualized with a grounded theory approach. The results confirmed the co-existence of the three logics in the power dynamics between employers, unions, regulators and workers. It is found that the production and the protection logic leads to paradoxical effect of their desired goals, and a reconciling logic emerges in the bottom-up initiatives which aims for community building and leads to improvement in both safety and productivity. However, the reconciling logic was found incomplete and handicapped due to the lack of involvement at senior management level and the production side of the project organization.