The hazard
Summer brings long days, high heat, strong sun, storms, bugs and new seasonal workers who do not know the site yet. Heat illness can come on fast, and a tired, overheated worker is more likely to make mistakes. There is no final federal OSHA heat standard, but water must be provided and the general duty to train still applies. Some states have their own heat rules, so check yours.
The action
An adequate supply of potable water must be provided at every place of employment. Keep it close to the work, not back at the trailer, and drink small amounts often, even before you feel thirsty. Rest in the shade when you can, and watch each other for headache, dizziness, cramps or confusion. (29 CFR 1926.51(a)(1))
ASK THE CREW
Where are the water and shade on this job, and how far are they from the work?
From the talk: Summer safety. Read it in full, free, with the questions and the sign-in sheet.