We've made the case for hydration being part of heat stress mitigation rather than being the solution, but understand that a urine colour chart may be helpful for some workers. The issue with the vast majority of these charts is the incorrect recommendation that clearer urine is better, and therefore, that greater fluid consumption is better. The best urine colour chart we've seen is from Healthline (see Figure 1 or here ). Not only does it reference overhydration, but the colour descriptors are unique and are likely to resonate with workers. Figure 1. Urine Colour Chart (Credit - https://www.healthline.com/health/hydration-chart)