Skip directly to search Skip directly to A to Z list Skip directly to navigation Skip directly to page options Skip directly to site content

Heat Stress: First Aid for Heat Illness


Cooling is key. Know the symptoms and treatment of heat illness.

Things you need to know:

  • Heat illness can strike quickly – learn to recognize the symptoms.
  • Workers with heat illness should stop working, get cool, and drink fluids.
  • Altered mental status can be a sign of heat stroke and requires immediate attention.
  • A potential heat stroke victim cannot be ignored or left alone—heat stroke is often fatal.
  • When treating severe heat illness, cooling is the priority. Cooling rapidly can help prevent heat exhaustion from progressing to heat stroke, and can improve the chances of surviving heat stroke.


Types of Heat Illness

Vertical arrow changing color from yellow to red from top to bottom. It is labeled "less severe" in the yellow area, "severe" in the orange area, and "often fatal" in the red area.

Signs and Symptoms

These can occur in any order.

What to Do
Heat Rash/Prickly Heat
  • Miliaria rubra: cluster of red bumps, pimples, or small blisters, usually on neck, upper chest, groin, under breasts, and in elbow creases
  • Miliaria profunda: Extensive areas of skin that do not sweat on heat exposure, but present gooseflesh appearance that subsides with cool environments
  • When possible, a cooler, less humid work environment is the best treatment.
  • Keep rash area dry.
  • Powder may be applied to increase comfort.
  • Do not use ointments or creams, as they may impair cooling. Warm, moist skin may make the rash worse.
Heat Cramps
  • Muscle cramps, pain, or spasms in the abdomen, arms, or legs
  • Drink water and have a snack every 15 to 20 minutes.
  • Avoid salt tablets.
  • Get medical help if the worker has heart problems, is on a low sodium diet, or if cramps do not subside within 1 hour.
Heat Syncope
  • Fainting (short duration), dizziness, or light-headedness during prolonged standing or suddenly rising from sitting/lying position
  • Sit or lie down in a cool place when beginning to feel faint or dizzy.
  • Slowly drink water, clear juice, or a sports drink.
Heat Exhaustion
  • Headache
  • Nausea
  • Dizziness, weakness
  • Irritability
  • Thirst, heavy sweating
  • Elevated body temperature
  • Decreased urine output
  • Call for medical help or take worker to a health facility for evaluation and treatment.
  • Stay with worker until help arrives.
  • Remove worker from hot area and give liquids to drink.
  • Remove outer clothing, including shoes and socks, hard hat, and long-sleeved garments.
  • Cool worker by any means available—you can use cold compresses, or have the worker wet head/neck/face/body with cold water. You can also use ice, cooled bed sheets, or fans for cooling.
  • If the worker can drink, give them the worker plenty of cool water, but do not give water to an unconscious person or someone unable to drink.
  • Do not leave the worker alone. Someone should stay with the worker until it is clear he or she is recovering.
 Heat Stroke
  • Confusion, altered mental status, slurred speech, loss of consciousness
  • Hot, dry skin or profuse sweating
  • Seizures
  • Very high body temperatures
  • Fatal if treatment delayed
  • If a co-worker shows signs of confusion or altered mental status while working in the heat, he or she needs help fast!
    • Use company protocol to get the worker to emergency medical care immediately, cooling during transport.
  • Move worker to a cool area and remove outer clothing.
  • Cool worker as quickly as possible with cold water, an ice bath, or iced bed sheets.
    • Prepare iced bed sheets by placing bed sheets in a cooler filled with 1/3 water and 2/3 ice.
  • Circulate air around worker to speed cooling.
  • Place cold, wet cloths or ice on head, neck, armpits, and groin. Continue cooling until medical care arrives.
  • Stay with worker until he or she reaches emergency medical care.

Case Study: Heat Stroke

Ambulance workers attending to a patient.A 44-year-old male worker died of heat stroke while working on a North Carolina farm. The man had been working in the fields for about a week. On August 1st, the heat index was between 100 °F and 110 °F. Around 3 p.m., the worker complained to the crew leader that he was feeling ill. He drank some water and was driven to the employee housing and left alone. He was found unconscious 45 minutes later. Emergency personnel took the worker to the hospital, where he was pronounced dead. His core body temperature was 108 °F.

Lessons Learned
  • Feeling ill while working in the heat is a serious warning sign. Any employee who reports feeling unwell during work in hot conditions could have heat exhaustion, which can quickly progress to heat stroke if not treated.
  • Proper first aid for someone with suspected heat exhaustion or heat stroke involves COOLING the body as quickly as possible—not simply drinking water.
  • People with severe heat illness do not always recognize the risks they face. If a worker shows signs of heat exhaustion or heat stroke, do not leave him or her alone until he or she receives medical attention.