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
Summer storms build fast. When you hear thunder, stop outdoor work and get inside a building or a hard-topped vehicle. Work on scaffolds is not allowed during storms or high winds unless a competent person decides it is safe and workers are protected by personal fall arrest or wind screens. Wait until the storm has clearly passed before going back out. (29 CFR 1926.451(f)(12))
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.