Hydration & Nutrition on the Job

Physical work in heat, cold or heavy PPE burns energy and drains water from your body. Even mild dehydration causes fatigue, headaches, cramps and poor concentration, and it’s a big step toward heat illness. What you drink and eat affects how safely you work.

• All workers
• Outdoor workers

How much water

• In hot conditions, OSHA recommends drinking about 1 cup (8 ounces) every 15 to 20 minutes, even if you aren’t thirsty.
• Don’t wait for thirst; by then you’re already behind.
• Start the day hydrated, and keep drinking after work.
• Don’t drink huge amounts all at once; steady sips work better.

Signs of dehydration

• Dark yellow urine, or not needing to urinate much
• Thirst, dry mouth
• Headache, dizziness, tiredness
• Muscle cramps
• Trouble concentrating

Pale yellow urine is a good sign. If symptoms get worse (confusion, vomiting, fainting), treat it as heat illness and get help. See Heat Illness.

Electrolytes and sports drinks

When you sweat heavily for more than a couple of hours, you lose salt as well as water. Regular meals usually replace it, but on long, very hot shifts an electrolyte drink can help. Watch the sugar content, and keep water as your main drink.

Energy drinks and caffeine

• A little caffeine is fine for most people, but large amounts can cause a racing heart, anxiety and poor sleep.
• Several energy drinks a day, especially in heat, can be risky. They don’t replace sleep or water.
• Avoid alcohol the night before hot, heavy work; it dehydrates you.

Eating for energy

• Eat breakfast. Starting a physical shift on an empty stomach drains you by mid-morning.
• Pack food that keeps you going: protein, whole grains, fruit and vegetables.
• Eat smaller meals and snacks through the day rather than one huge lunch.
• Keep food cool and wash your hands before eating, especially after working with lead, concrete or chemicals. See Sanitation.

Employer responsibilities

OSHA requires employers to provide drinking water and toilets, and heat illness rules in several states require cool water, shade and breaks. See Sanitation and Heat Illness.

Last updated: October 2, 2026