#261 Heat Illness Water

Revised Regulation – Effective May 1, 2015:


There must be an adequate supply of clean, cool, potable water. Employees who are working outdoors in the heat need to drink 1 quart of water per hour, including at the start of the shift, in order to replace the water lost to sweat. For an eight-hour day this means employers must provide two or more gallons per person. Thirst is an unreliable indicator of dehydration. Employees need ongoing encouragement to consume adequate fluids.


  • Potable drinking water must be made available at no cost to the employee.
  • Maintain, at all times, sufficient quantities of pure and cool potable drinking water (i.e. enough to provide at least one quart per employee per hour for the entire shift).
  • Water must be fit to drink. Water containers CANNOT be refilled from non-potable water sources (e.g. irrigation wells, sprinkler or firefighting systems).
  • Care must be taken to prevent contamination of the drinking water supplied to the workers.
  • Implement and maintain effective replenishment procedures when beginning the shift with smaller quantities.
  • Locate the water containers as close as practicable given the working conditions and layout of the worksite.
  • Keep it readily accessible, move it with the workers!
  • Encourage the frequent drinking of water.