Appendix B: Hydration Techniques
For most employees who are well acclimated to exterior conditions in the work environment, proper hydration is a simple matter of drinking sufficient potable water prior to exposure to heat, and at least one quart per hour of cool potable water during the work involving exposure to high heat. Drink before you get thirsty. If you are working in high heat conditions, and become thirsty, you cannot replace the fluid loss you have sustained orally.
To re-state what Cal/OSHA recommends, an employee must consume up to four (4) cups per hour of cool, potable water during work in high heat conditions. For reference, a 500 ml bottle of commercially available water is equal to approximately two (2) cups of water. Thus, consuming two (2) 500ml bottles of water per hour would be equal to 4 cups.
Preventing heat related illness in employees is preferable to responding to a victim of heat illness, It is very important to “pre-hydrate” prior to beginning work in a high heat environment. If possible, employees should consume at least one bottle of water, or 2 cups, before beginning work in a high heat environment.
The Cal/OSHA standard requires employers to provide potable, “cool&” water for employees. For reference, university public drinking fountains that are not electrically refrigerated provide water at between 75° F and 76° F. If supervisors choose to supply drinking water out of insulated water coolers, the contents needs to be kept at that relative temperature. Additionally, if a water cooler is provided, it must be sanitary, and have a valve for dispensing the water into individual cups, on for each employee, or disposable cups. The use of a communal dipper is not permitted.
The use of salt pills, or electrolyte replacement “sports” drinks is not recommended for normal hydration and fluid replacement. Water is the preferred fluid, taken in the amounts discussed. Do not over-hydrate, or try to consume more that the recommended amount and rate. Water intoxication can occur, where so much water in ingested that electrolyte balance is disturbed, which can lead to heart arrhythmias and other circulation problems.
In summary, anticipate high heat conditions, ensure that heat illness risk factors are eliminated or controlled, pre-hydrate before beginning work in high heat and humidity, and consume at least four (4) cups of water per hour during work in high heat.
Know the signs and symptoms of heat related illness. Keep an eye on co-workers, and respond quickly when you see signs of heat related illness in others.