Working outside is a daily reality for many who make their livelihood farming or hobby gardening. In the summer that can mean long hours in hot, humid conditions. Know the signs of heat illness and ways to prevent it to make sure you can be productive this summer.

“Heat illness occurs when the body can no longer cope and the body’s physical and mental functions break down,” explains the Upper Midwest Agricultural Safety and Health Center.

The National Ag Safety Database (NASD) says your ability to sweat declines with age, so people over 40 should take extra precautions when it is hot. In humid conditions, perspiration can’t evaporate as readily to cool you off.

Staying hydrated is one of the most important ways to reduce the risk of heat illness. “The rate of water intake must equal the increased rate of water loss by perspiration to keep body temperature normal,” explains one NASD resource.

Hard work in hot conditions can result in a range of heat illnesses. Take breaks to hydrate and cool off. Don’t push yourself if you feel ill. You could put yourself or coworkers at a higher risk of having an accident or deadly heat stroke.

Keep an eye on coworkers. If someone is weak, confused, or behaving strangely, they may be suffering from heat stroke.

“Symptoms include heavy sweating, cool, moist skin, body temperature over 100.4°F., weak pulse, and normal or low blood pressure. The victim is likely to be tired, weak, clumsy, upset, or confused. They will be very thirsty, and will pant or breath rapidly. Their vision may be blurred,” a NASD resource says.

You should call for help immediately. Heat stroke can be deadly. Once help is on the way you can move the person to a cool area and offer them cool, lightly-salted water to drink. Loosen or remove excess clothing, fan, and gently spray the victim with cool water.