Summer Days Ahead: Don’t Ignore Heat Stress!

Mary Ann Rose, Pesticide Safety Education

With the arrival of summer, the risk of heat stress increases.  Farmers have an elevated risk of heat stress for obvious reasons – working outdoors.  Activities that require protective clothing, such as pesticide application, further increase the risk.   

Heat stress is a condition that develops with increasing body temperature. The body has mechanisms to eliminate excess heat that we can readily observe, such as perspiration and flushing. If the body’s ability to cool itself is overwhelmed, heat stress may progress to a life-threatening condition – heat stroke.   Heat stress also may contribute to other serious health conditions, such as heart attacks, and because of fatigue or confusion that may be associated with heat stress, may contribute to higher incidence of accidents or injuries.   

Protect yourself, your family and farm workers by implementing preventive measures and knowing the danger signs of heat stress.   

The following measures can lower the risk of heat-related illness:

  • Drink plenty of water to stay hydrated; avoid alcohol and caffeinated beverages. During heavy work in heat, the body may lose as much as 1-2 quarts per hour! 
  • Adapt work to the weather, for example, spray pesticides at cooler times of the day.
  • Take breaks to cool down, for example, 10-15 minutes every 2 hours.
  • Wear loose-fitting, lightweight clothing whenever possible.
  • Read medicine labels for interactions with sun and heat; some drugs may increase sensitivity.
  • Build up a tolerance to working in the heat.
  • Wear hats and sun protection if working outside.
  • Be conscious of health conditions that may increase with heat stress.

Signs of heat stress and heat stroke

People may begin feeling hot, tired, and sweaty.  Excessive heat and resulting dehydration can lead to heat exhaustion symptoms which may include headache, light-headedness or dizziness, fatigue, loss of strength, cramps, severe thirst, dry mouth, and mood changes. As conditions progress towards potentially life-threatening heat stroke, symptoms also may include lack of sweating, dry skin and elevated body temperature, confusion or aggression, fast pulse, convulsions, and loss of consciousness.  

How to help someone experiencing heat stress

Get the person to a cooler, shaded area as soon as possible and give them cool water to drink, in small amounts, but as much as they can drink.  Loosen or remove any tight protective gear or outer clothing, especially around the neck, chest, and waist.  Splash the person’s body with cool water or apply wet towels; change the towels frequently to keep them cool. Fan the person with a hat or other item. If the person does not respond quickly to first aid or if they are experiencing the heat stroke symptoms, get medical assistance immediately.   

For additional information on symptoms and first aid measures, read the following resources:

Heat Stress (factsheet)

Heat Stress. Farmworker Health and Safety

Mary Ann Rose, Director, Pesticide Safety Education Program can be reached at (614) 292-4070 or The Pesticide Safety Education Program website is located at

This column is provided by the OSU Extension Agricultural Safety and Health Team,