SL
Sondra Lavoie
CSP, CHST, AVP Risk Control Specialist, North America, Insurance
Newsletter
Heat Related Illness
In the midst of a scorching summer, heat illness and dehydration become critical factors that can significantly impact health and performance.
Heat-related illnesses on the job: staying hydrated is the key
The human body relies on a delicate balance of temperature regulation and fluids to function optimally. When disrupted—especially in hot and humid conditions—individuals are at risk of developing various forms of heat-related illnesses.
According to the US Department of Health and Human Services, heat-related deaths have seen a steady increase, with approximately 2,302 occurring in the US in 2023, compared to 1,722 in 2022 and 1,602 in 2021.
Understanding these conditions and implementing proper heat illness management and hydration strategies are paramount for preventing adverse health outcomes and keeping employees working in high-heat environments safe.
Proper hydration is fundamental in preventing heat-related illnesses. Water is essential for thermoregulation, aiding in sweat production and maintaining blood volume.
Heat illness: types and symptoms
Heat illness encompasses a spectrum of conditions ranging from mild discomfort to severe, life-threatening emergencies. The primary forms of heat illness include heat cramps, heat exhaustion and heat stroke:
-
Heat cramps
Often the mildest form, heat cramps manifest as painful muscle spasms that occur during or after intense physical exertion in hot conditions. They are usually caused by electrolyte imbalances and dehydration. -
Heat exhaustion
More serious than heat cramps, heat exhaustion results from prolonged exposure to high temperatures and inadequate fluid intake. Symptoms include heavy sweating, weakness, dizziness, nausea, headache and sometimes fainting. -
Heat stroke
The most severe form of heat illness, heat stroke occurs when the body’s core temperature exceeds 104°F (40°C). It is a medical emergency that can lead to organ damage, brain injury and even death if not promptly treated. Symptoms include confusion, agitation, hot and dry skin (in classic heat stroke) or profuse sweating (in exertional heat stroke), rapid heartbeat and unconsciousness.
Risk factors for heat illness
Several factors increase susceptibility to heat-related illnesses:
- Environmental conditions: High temperatures, humidity and lack of airflow contribute significantly.
- Physical factors: Age, obesity, certain medical conditions (such as heart disease) and medications (such as diuretics) can impair heat tolerance.
- Lifestyle and occupation: Individuals who work outdoors in high-heat environments, especially in protective clothing, are at increased risk. Indoor roles with elevated temperatures, limited ventilation or PPE that adds to heat load are also at risk—particularly in high-exertion jobs.
Hydration: the key to prevention
Proper hydration is essential for preventing heat-related illnesses. Water supports thermoregulation, enables sweat production and helps maintain blood volume.
Dehydration exacerbates heat stress, making it critical to consume adequate fluids before, during and after exposure to hot environments or physical activity.
Heat illness and hydration management are vital for maintaining health and safety—particularly in hot climates or during strenuous work.
According to the USGS, approximately 60% of the human body is water, and all bodily systems rely on hydration to:
- Flush toxins from vital organs
- Carry nutrients to cells
- Maintain moisture levels in tissues
When we sweat, we lose electrolytes such as sodium, potassium and calcium—key to chemical balance in the body. The Mayo Clinic estimates that the body loses 8–12 cups of water daily through breathing, perspiration and urine.
To function correctly, the body must replenish fluids through beverages and water-rich foods such as fruits and vegetables—particularly when heat risk increases.
In hot weather, skip coffee or soda and prioritise water. You may also consult a healthcare professional regarding electrolyte drinks or supplements to support hydration.
Hydration guidelines
-
Pre-activity
Being hydrated before work makes it easier to stay hydrated throughout the day. -
During activity
Drink before you feel thirsty. Consume approximately 8 ounces of fluid every 10–20 minutes. Do not exceed 48 ounces per hour. -
Post-activity
Rehydrate after work. This is particularly important as recovery takes time. Chronic dehydration can lead to additional health issues. -
Electrolytes
Electrolytes lost through sweat should be replenished. Sports drinks or electrolyte-enhanced water can help maintain balance. Consult a medical professional for appropriate intake. -
Monitoring hydration status
Urine colour and frequency can indicate hydration levels. Light-coloured urine suggests adequate hydration, while darker urine may indicate dehydration.
Preventive measures and treatment
Prevention
- Acclimatisation: Gradually increase exposure to hot environments to allow the body to adapt
- Clothing: Wear lightweight, loose-fitting and light-coloured clothing
- Rest and shade: Take regular breaks in shaded or cool areas
Response to heat illness
If someone shows signs of heat illness:
- Immediate cooling: Move them to a cooler area, remove excess clothing and apply cold packs or cool water
- Fluid replacement: Provide cool water or sports drinks if the individual is conscious and able to drink
Conclusion
Heat illness and hydration management are critical for maintaining health and safety, particularly in hot climates or during strenuous work.
Understanding the types, symptoms, risk factors and preventive measures associated with heat illness is essential for both individuals and employers.
By prioritising hydration, monitoring conditions and responding early to symptoms, risks can be reduced—supporting safer and more productive working environments.
OSHA has developed heat illness management guidelines, and some states, including California, have introduced specific regulatory requirements. Reviewing these resources can strengthen prevention efforts.
Contact your Sompo Risk Control Specialist or reach out at +1 877 667 5733 or RiskControlQuestions@sompo-intl.com to discuss safeguarding your property and people with confidence.
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Risk A/T® Work - Heat-related Illnesses on the Job: Staying Hydrated is the Key
In the midst of a scorching summer, heat illness and dehydration become critical factors that can significantly impact health and performance.
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