When working outdoors in the summer, heat stress and sun exposure are often grouped together, but they are not the same thing. Understanding the difference can help prevent serious health risks and improve overall workplace safety.
Heat Stress: A Body Temperature Emergency
Heat stress occurs when the body absorbs more heat than it can release. This can result in heat exhaustion or, in severe cases, heat stroke. The primary causes of heat stress include:
- High temperatures and humidity
- Heavy physical exertion
- Inadequate hydration
- Poor ventilation or lack of shade
SYMPTOMS OF HEAT STRESS:
- Dizziness or confusion
- Heavy sweating or lack of sweating (in severe cases)
- Rapid heartbeat
- Muscle cramps
Sun Exposure: The Hidden Skin and Eye Hazard
Sun exposure is the direct impact of ultraviolet (UV) radiation on the skin and eyes. Even on a cool day, excessive sun exposure can cause harm, including:
- Sunburn
- Skin damage leading to long-term conditions such as skin cancer
- Eye damage, including cataracts
Open the 2026 Summer Scorcher. A Heat Stress Prevention Guide.
View our Heat Stress category for hydration, cooling protection, and more!
PROTECTING YOURSELF:
- Wear UV-rated sunglasses to protect your eyes.
- Apply broad-spectrum sunscreen (SPF 30+), even on cloudy days.
- Wear light-colored, long-sleeved clothing and a wide-brim hat for extra protection.
How Sun Exposure and Heat Stress Work Together
While heat stress is related to internal body temperature regulation, sun exposure increases the risk of heat stress by raising body temperature. Workers who are exposed to direct sunlight for long periods are more likely to overheat. Additionally, sunburned skin loses its ability to regulate temperature effectively, making heat stress more dangerous.
Prevention Strategies for Outdoor Workers
- Hydrate constantly: Drink water regularly, even before you feel thirsty.
- Seek shade: Take breaks in shaded or air-conditioned areas when possible.
- Dress smart: Wear cooling PPE and light, breathable fabrics.
- Use sunscreen: Apply and reapply throughout the day.
- Know the signs: Recognize early heat stress symptoms and take immediate action.