It has long been known that work in the heat can compromise health and safety and lead directly or indirectly to worker injury and death. This project, sponsored by the Health and Safety Executive in the United Kingdom, was conducted to ensure that developments in heat stress assessment were evaluated and where to advantage, included in assessment methods appropriate for use in British industry.

The project presented in this report is unique in that it addresses the issues of both validity and usability. It was conducted in parallel with a number of national and international initiatives into heat stress assessment.