One of the most important things to safely work in the heat and prevent heat illness is drinking enough fluids.

Resources:

https://www.cdc.gov/niosh/mining/UserFiles/works/pdfs/2017-126.pdf

https://www.cdc.gov/niosh/topics/heatstress/recommendations.html

https://www.osha.gov/heat-exposure/water-rest-shade

https://www.ncbi.nlm.nih.gov/books/NBK236237/