Landscape company does not provide water.

I work for a landscaping company in the South. I am in Tennessee and days such as today the highs will be in the mid 90's, with a real feel of 118° and of course nasty 80% humidity. My boss refuses to buy/provide coolers with water on any of the crew trucks. We work 10-12 hour days. He states that he bought them a few years ago and will not again, Some job sites we are on for 4-6 hours at a time without being able to leave and if someone didn't have enough money to buy even a bottle of water then they are just going thirsty. At times we have even went directly to job sites with the foreman even going to a convenience store. I personally have had a few episodes of dehydration and even fell out because my muscles locked up. Any thoughts?