Keeping Workers Well-Hydrated

Why Hydration is Important

Your body heats up as you work and cools itself through sweating. Sweating 

can lead to dehydration. Proper hydration is essential in preventing heat illness.

Water

Drinking water frequently and eating 

regular meals is usually sufficient for 

hydration.

Electrolytes

For sweating that lasts several 

hours, sports drinks can help replace 

electrolytes that workers lose when 

working in hot environments. Salt 

tablets are not recommended unless 

a worker is instructed by their doctor. 

Most people can restore electrolytes 

through regular meals. Additionally, 

consuming too much salt may lead 

to nausea and vomiting which can 

worsen dehydration.

Alcohol

Alcohol can increase your risk of heat 

illness because it is a diuretic. Diuretics 

lead to dehydration.

Caffeine

In general, a normal amount of caffeine will 

not influence your overall hydration. When 

your heart is strained from hot temperatures 

and workload, high caffeine levels can add 

additional strain on your heart. Workers 

should keep this in mind: some energy drinks 

contain more caffeine than coffee.

Medications

Certain medications, like diuretics, can 

lead to an increase in urination. If a 

worker is not keeping up with their water 

intake, they are at risk of dehydration.

How Different Products Play into Hydration
Tips for Employers 

To prevent heat illness among indoor and outdoor workers, it is important for employers 

to ensure workers are hydrated, have easy access to water, and can rest. 

Maintaining a cool or shaded 

rest break location:

Outdoors: This might mean a shady 

area, an air-conditioned vehicle, a 

nearby building or tent, or an area 

with fans and misting devices.

Indoors: Workers should be allowed 

to rest in a cool or air-conditioned area 

away from heat sources (e.g., ovens, 

furnaces).

Equipping all work areas with 

accessible and visible cool water 

(i.e., temperature less than 60° F). Motivating workers to keep a 

sealable bottle of cool water in 

their work area so that they can 

Encouraging workers to drink at continuously hydrate.

least one cup (8 ounces) of water

every 15-20 minutes while working 

in the heat, not just when they are 

thirsty. Do not drink more than 48 

oz (11⁄2 quarts) per hour! Drinking 

too much water or other fluids 

(sports drinks, energy drinks, etc.) 

can cause a medical emergency 

because the concentration of salt in 

the blood becomes too low.

Consider providing electrolyte 

products when workers perform 

strenuous, sweat-producing job 

tasks for extended periods of time.

Employers can encourage proper hydration by:

Educating workers on the 

importance of hydration and 

what should be avoided.

Designating a relief person so that 

workers can take a water break 

or having water brought directly to 

workers that cannot leave their 

work area.
When working in the heat, drink 1 cup 

(8 ounces) of water every 15–20 minutes. 

This is about 32 ounces of water every hour, 

however, this should not exceed the 48 oz.

Along with continuous drinking, take your 

scheduled meal breaks as food will help in 

replacing the electrolytes lost from sweat.

How much is 32 ounces?

1 QUART 1/4 GALLON 1 LITER

Sources: 

Heat Stress: Hydration | CDC | Keeping Workers Hydrated and Cool Despite the Heat | Blogs | CDC

Federal law entitles workers to a safe workplace. Workers have the right to speak up about hazards without 

fear of retaliation. See www.osha.gov/workers for information about how to file a confidential complaint with 

OSHA and ask for an inspection. 

1-800-321-OSHA (6742) | TTY 1-877-889-5627 | www.osha.gov/heat

Tips for Indoor and Outdoor Workers

Pro tip: There are misconceptions around the safety of cold water. 

Consuming water—whether it is cold, cool, or room temperature—

when you’re dehydrated is important for preventing heat illness.

Source: Sustainable solutions to mitigate occupational heat strain 

| NCBI

Scan for more information 

on heat illness prevention

Being hydrated before you 

begin work makes it easier for 

you to stay hydrated throughout 

your shift.

Hydrate Before Work

Dehydration can happen fast, so 

make sure to drink cool water 

throughout your shift even when 

you do not feel thirsty.

Hydrate During Work

Be sure to replace the fluids 

you lost while working. 

Hydrating after work reduces 

the strain on your body from 

dehydration. Hydrating after 

work is even more important if 

you work in a hot environment 

on a regular basis. Chronic 

dehydration increases the 

risk for medical conditions, 

such as kidney stones. 

Hydrate After Work

OSHA 4372-09 2023