In 2016-17, the Bangladesh Ready-Made Garment (RMG) industry generated USD28.14 billion, contributing 80.7% export earnings and 12.36% GDP, and employing 4 million people. Working conditions inside RMG factories are often difficult. Heat stress is a major factor which is expected to worsen in future due to global warming. The paper reports on a project to understand the exact nature of the heat stress risk to factory workers at present and in a future warmer world, and to explore the potential to introduce sustainable cooling strategies which would reduce reliance on greenhouse-gas-intensive energy sources. The project is based on exploration of two RMG factory buildings (one cooled principally by fans and the other by ducted downward-flowing cooled air) in Dhaka. A range of tools were used including climate-controlled chambers, worker interviews, indoor environmental modelling and data collection of internal and external climate variables (e.g. temperature, humidity, wind speed). The project is described and some preliminary results are presented.