Preventing Heat Illnesses in Agriculture
This is especially the case when temperatures and humidity are high. Knowing about the symptoms and how to respond could be life-saving.
What Are the Symptoms, and Who is at Risk?
Our bodies have several ways of cooling themselves (e.g., perspiration and evaporation). Heath-related illnesses occur when one of these cooling mechanisms fails. The National Institute for Occupational Health and Safety (NIOSH) uses the Wet-Bulb Globe Temperature (WBGT) to assess the risk for heat stress. The following guidance is for the type of work being done and temperature limits for acclimated workers.
- Light work: WBGT up to 86 degrees F
- Moderate work: WBGT up to 82 degrees F
- Heavy work: WBGT up to 77 degrees F
We are all at risk of sustaining a heat-related illness, but the following groups may run a higher risk of developing a heat-related illness:
- Older populations
- Infants
- Individuals with certain medical conditions, such as circulatory and/or heart problems, or who are pregnant
- Individuals who are physically unfit or overweight
- Individuals who have just consumed alcohol and/or drugs (including prescription medications)
- Those workers who do not have adequate fluid intake levels
- Individuals with a lower heat tolerance level or those who have not fully acclimated to working in the heat
- Individuals working in areas of high temperatures and humidity levels of specific environments (e.g., heat-conducting surfaces)
- Workers completing jobs in areas that have limited airflow to help with the cooling process
Preventing Heat-Related Illnesses
You can take a number of steps to prevent heat-related illnesses. Before outside work begins:
- Check your prescription and over-the-counter medications to determine if there are side effects when exposed to heat.
- Talk to your physician if you have a chronic health condition to obtain any special recommendations for working in hot and humid environments. If you are a farm owner or manager, teach your workers about the prevention and emergency response of heat-related illnesses. You can use the following resources to help you plan for that training and to post reminders: Heat Illness Prevention Materials from the Pacific Northwest Agricultural Safety and Health Center and Heat and Sun Protection Safety posters (available in English and Spanish) from the New York Center for Agricultural Medicine and Health.
When Working Outside:
- Wear lightweight, breathable, loose clothing and light colors that reflect sunlight and a wide-brimmed hat.
- Drink approximately eight oz. (1 cup) of water about every 15–30 minutes. (Note: Do not wait until you are thirsty to drink water!)
- Avoid caffeine, alcohol, drugs, and large amounts of sugar, and limit your salt intake because they can speed up the dehydration process.
- Pace yourself and take 15-minute breaks in the shade every two hours.
- Save strenuous work for the cool times of the day, such as early morning or evening, and reschedule those tasks that require personal protective equipment.
- Gradually adjust to working in the heat. For example, when you have a new employee, train them about heat illnesses and schedule their outside hours for shorter periods with breaks for one to two weeks as they acclimate.
- Throughout the day, observe your employees for heat-related problems and reinforce best practices.
- Change work schedules and routines if the heat and humidity index exceeds 105°F. Use a tool like the OSHA-NIOSH heat safety tool app to monitor working conditions.
Types of Heat-Related Illnesses and What to Do
These are five heat-related illnesses to be on the lookout for, listed from least to most severe:
| Heat Illness | What to look for | What to do if it happens |
|---|---|---|
| Heat Rash: caused by excessive sweating during humid weather when sweat does not evaporate from the skin and clogs pores. | - Red, blotchy skin rash or areas with clusters of pimples or small blisters. - Severe heat rash can develop into an infection. |
- Keep the affected area dry. - Treat with corn starch or powder. - Rest in a cool place. |
| Heat Syncope, or fainting, affects people who aren't used to working in the heat or sitting/standing for long periods. It happens when the body pumps warm blood to the skin surface to remove heat via conduction, radiation, and convection. Heat syncope is not serious, but it can be scary to the victim or cause secondary injuries from falling. | Lightheaded, fainting, or dizziness | - Move the person to a cool place; they should lie down and elevate their feet. - Give the person plenty of cool fluids. - Contact a doctor if they do not get better. |
| Heat Cramps: caused by a loss of body fluids and electrolytes via sweating, which can upset the body's chemical balance. Cramps can happen during or after physical activity | - Pain or muscle spasms in the abdomen, arms, and/or legs. - It can be excruciatingly painful. |
- Stop the activity and wait several hours before returning to strenuous work. - Have the person sit down in a cool, shaded area. - Have the person drink plenty of water or cool beverages. - Seek medical care if cramps persist. |
| Heat Exhaustion: caused by a loss of body fluids and salts from heavy sweating and decreased blood flow to the brain and other organs. | Cool, pale, clammy skin; dizziness; heavy sweating; headache; cramps; nausea or vomiting; weakness; lightheadedness; confusion; thirst; irritability; or even unconsciousness. | - Contact emergency medical services if symptoms do not improve within 60 minutes. - Have the person sit or lie down in a cool, shaded area. - Remove excess clothing and apply cool compresses. - If conscious, give plenty of cool fluids while waiting for help to arrive. - The person should not return to work that day. |
| Heat Stroke: complete failure of the body's temperature-regulating mechanisms and a medical emergency. | - Hot, dry skin; temperature of 105 degrees or higher; confusion; anger; chills; nausea; dizziness; unconsciousness, convulsions; and delirium. - In severe cases, the person can become comatose. - If not treated immediately, heat stroke may be fatal. |
- Immediately contact emergency medical services. - Move the person to a cool place and provide them with water to drink. - Remove outer clothing and cool the body (e.g., cool water, wet towels or sheets, or immersion). - Slightly elevate their head and shoulders. - Cool the body by using cool water, fan, cold packs, wet towels, etc. |
As a general rule, contact first responders if a person exhibits any of the following signs:
- Body temperature: Over 103 degrees
- Skin: Their skin is hot and red
- Heart rate: Fast, strong pulse
- Cognitive: Person is confused or has lost consciousness.
Additional symptoms that require immediate care include:
- Vomiting
- Dark urine or decreased urine output
- Symptoms lasting more than 1 hour: cramps, dizziness, headache, and nausea.
Summary
Heat-related illnesses can be potentially dangerous and life-threatening to those individuals in a farming community, but they can be prevented. When working outdoors, drink plenty of water before and during work activities, take breaks in a shaded area, pace yourself, and gradually adjust to working in the heat.
Resources
Brown, K., Komar, S., Infante-Casella, M., and Bamka, W. (2024). Preventing heat stress in agriculture. Rutgers Cooperative Extension.
Heat illness. (n.d.) New York Center for Agricultural Medicine and Health.
Heat illness prevention (n.d.) U.S. Department of Labor - Occupational Safety and Health Administration.
Heat illness prevention materials. (n.d.) Pacific Northwest Agricultural Safety and Health Center.
Heat-related illnesses and agricultural producers. (2024) Ag Safety and Health eXtension Community of Practice.
Heat-related illnesses and first aid. (n.d.) U.S. Department of Labor – Occupational Safety and Health Administration.
Preventing heat-related illnesses. (n.d.) High Plains Intermountain Center for Agricultural Health and Safety.
Protecting workers from the effects of heat (PDF). (2023) Occupational Safety and Health Administration.
Original authors: Dennis J. Murphy, retired Professor, Agricultural Safety and Health.
Article updated by Florence Becot, Nationwide Early Career Professor of Agricultural Safety and Health and Linda Fetzer, Extension Program Specialist.
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