“There’s a whole spectrum of heat-related illnesses to be aware of,” says Eugene Hong, M.D., associate professor and chair, Department Family, Community & Preventive Medicine at Drexel University College of Medicine.

“People need to be aware of heat-related symptoms and take proper precautions not to ignore any abnormal signs they may be experiencing due to the heat,” says Hong, who is also chief of the Division of Sports Medicine.

Warning signs of a heat-related illness include feeling light-headed, dizzy, short of breath or nauseous. Symptoms of heat stroke – the most severe of heat-related illness – include confusion, loss of consciousness, and any mental status changes. Another telltale sign of heat stroke is a core body temperature of 104°F or higher, in which case it becomes a medical emergency.

“We really worry about older folks and the young (those under the age of 18) because they can’t regulate their body temps as well as adults can,” explains Hong. “People do die of heat-related illnesses, which are completely preventable.” In fact, heat is the number one weather-related killer in the United States, according to the National Oceanic and Atmospheric Administration’s National Weather Service.

Hong says the body’s natural way of cooling itself down is to sweat. “If you think someone’s hot and they’re sweating, that’s a normal response to the heat. But, if they’re dry and cool, that’s a serious cause for concern, especially in babies,” he warns. “With infants you have to be even more careful because they can’t communicate how they’re feeling.”

Those with chronic medical conditions also need to be careful in the heat. That includes people suffering from heart disease, sickle cell, diabetes or asthma. Also, Hong warns that anyone taking antihistamines and other medications should be aware that those medications may affect the body’s ability to regulate core body temperature.

If you think you may be suffering from heat exhaustion, use common sense and take the normal precautions: find a cool place where there is air conditioning or at least a fan and stay well hydrated. If you are outside and can’t get indoors, find some shade. If symptoms persist or get worse, ask for help and if necessary, seek medical attention.