As Wisconsinites, we appreciate every bit of sunshine and warmth we get because we know it is entirely possible for Mother Nature to bring us snow in early fall. Spending time outdoors is good for the body — increased physical activity and vitamin D are two important health benefits. However, there are days when it is just too hot to safely be outside without risking any number of heat-related illnesses. According to the Centers for Disease Control and Prevention, above-average temperatures kill more than 600 Americans each year. Knowing the warning signs can help ensure a happy and healthy summer.


Water is essential for our bodies because nearly all of the major systems depend on it. Dehydration can be a serious concern for anyone spending time in the heat, particularly children and the elderly. Dehydration occurs when the body loses more fluid than it takes in and is usually caused by not drinking enough water to replace what is lost. In a hot climate, the body sweats as a cooling mechanism, so water and electrolytes are lost at a faster rate. Increase water consumption on a hot day, especially during periods of physical activity. Certain medications can also increase the risk of dehydration.

It can be tough to know when we are dehydrated because we might not necessarily feel thirsty. Dehydration symptoms can range from mild to severe, including dry mouth, fatigue, decreased urine or darker urine, headache and dizziness. Severe and persistent dehydration symptoms require immediate medical treatment. Call 911.


The skin is the body’s largest organ and acts as a protector for the muscles and organs, but without protection from the sun’s ultraviolet (UV) rays, it can burn. A sunburn is red skin that is sore to the touch and feels warm. Skin cancer, or melanoma, is the most prevalent of all cancers, and sunburn is the most preventable risk factor. Seeking shade; wearing long-sleeved pants, skirts and shirts; sunglasses; hats and sunscreen are effective in protecting the skin. I recommend sunscreen with a sun protection factor (SPF) of 30 or higher. Apply the sunscreen liberally to all exposed skin 15 minutes before going into the sun and re-apply repeatedly, at least every two hours.

Sunburns usually take several hours to appear after UV exposure, but if the skin is turning pink or red, move into the shade or go indoors. Seek treatment at an urgent care clinic if the sunburn causes blisters and brings on nausea and headaches. A trip to the emergency room may be necessary if the burn is accompanied by a fever, confusion, swelling or open blisters.

Heat rash

A heat rash manifests as tiny red bumps and an itchy sensation on the affected area of skin. These rashes are often known as “prickly heat” and commonly appear on the face, neck, chest and back. These are areas of the body that are near sweat glands. Prolonged exposure to heat as well as intense exercise in the heat can cause blockages in a person’s sweat ducts.

A heat rash usually resolves on its own when the skin cools. Should rashes become severe (swelling, pus, swollen lymph nodes or fever and chills) a visit to an urgent care clinic or your primary care doctor may be in order.

Heat Exhaustion and Heat Stroke

Heat exhaustion and heat stroke are both caused by overexposure to heat, usually following strenuous physical activity. Heat stroke is more serious because it can cause permanent damage to the body. Heat stroke is a form of hyperthermia and occurs when the body’s temperature is at 104°F or higher. The body’s natural temperature regulation mechanisms are overwhelmed and organs are susceptible to damage due to the elevated temperature and dehydration.

Heat exhaustion is a precursor to heatstroke. Symptoms include a rapid pulse, muscle cramps and excessive sweating. Symptoms may also include dizziness, fatigue, nausea and headache. At the first signs of any of these symptoms, move to a cool place, drink water and rest. If the symptoms do not resolve or if they worsen, call 911 immediately. Both heat exhaustion and heat stroke could mean a trip to the emergency room.

About the Author

Sunu Eapen, MD, is an internal medicine physician with the Froedtert & the Medical College of Wisconsin health network. Dr. Eapen sees patients at the Sunnyslope Health Center in Brookfield.