Dr. Roger Hicks
Summer means spending lots of time outside, with many reasons to do so, be it walking, gardening, swimming, boating, or more physically demanding activities such as competitive sports or outdoor work. And while the great outdoors offers many health advantages, extended strenuous activity in the heat can cause a heat-related illness. These seem to be more frequent, possibly due to global warming. Average global temperatures the past 5 years have been the highest ever recorded, and nine of the 10 hottest years have been this century (the other was 1998).
There is a spectrum of heat-related illnesses ranging from the least serious, heat rash or prickly heat – an irritation of the skin from excessive sweating – to heat stroke, the most serious. In between are heat cramps – muscle pains caused by heavy exercise in hot weather; heat syncope – dizziness or fainting as a result of overheating, and heat exhaustion, precursor to heat stroke.
Heat exhaustion is collapse due to strenuous exercise in the heat, with a mildly elevated body temperature and no change in mental function. Untreated, it can progress to heat stroke, a true medical emergency. Heat stroke is defined as a core body temperature of 104 or above along with brain dysfunction, such as confusion, irritability, emotional instability, altered consciousness, or even seizures. Damage to other organs and tissue is common, the mortality rate is high, and among those that do survive, serious long-term problems are not unusual.
Our bodies cool in four ways. Evaporation through sweating and breathing (think of a dog panting); convection, the transfer of heat to moving air or water, (like sitting in front of a fan); conduction, the transfer to a colder object (like laying on a cold floor or block of ice); and radiation, just beaming our heat out into the world. Sweating is the mainstay, but if we are dehydrated, we can’t produce enough sweat.
Heat-related illnesses are more likely to occur when the temperature and humidity are high. Dehydration, poor physical fitness, alcohol and some other drugs, including stimulants, make it more likely to occur. Carrying equipment and wearing protective gear in the heat also increase the risk.
Exertional heat illness is common among those who work outdoors, such as agricultural and construction workers, firefighters, and military personnel. Heat stroke is the one of the leading causes of death in young athletes every year, and it is on the rise. One third of ER visits for exertional heat illness in the U.S. are teenage male athletes and the rate is 11 times higher in football players than all other teen sports combined.
It’s not surprising that infants and elderly are at increased risk, as are those with certain medical conditions. And as most people know not to leave a small child (or a pet) alone in a car on a warm day. That is the number one cause of heat stroke in children under five.
Finally, a lack of acclimatization increases the risk of heat-related illness. Acclimatization is the body’s ability to improve its response to heat stress over time and is the most important factor determining how well an athlete withstands extreme heat.
Those who are often exposed to elevated temperatures will show an increased tolerance and the ability to work in high temperatures for longer periods of time. Acclimatization requires at least one to two weeks of gradually increasing exercise in the hot environment.
Fortunately, preventing heat-related illness is not complicated. It can be distilled down to three words: water, rest, and shade. Drink fluids on a schedule. rather than just when thirsty. If water does not appeal to you, electrolyte replacement drinks – natural ones – are a good alternative. Take frequent cooling breaks in the shade or if possible, in an air-conditioned space. Having access to a fan and/or a mister is helpful. And. of course, taking a dip in a river, creek, or pool will quickly help lower your body temperature.
If you pay attention, your body will let you know if you are overexposed or overexerted. Early warning signs of heat-related illness include cramps, fatigue, headaches, or light-headedness. If these symptoms are present, take a break, get into the shade, have something to drink and use whatever means available to cool down as soon as possible. If symptoms persist, seek treatment at your local urgent care center or emergency department.
The human body is a remarkably adaptive. Treat it well and enjoy these dog days of summer.
A director of the Urgent Care Association of America from 2011 to 2017, Dr. Roger Hicks served as the Association’s treasurer and then secretary. He is a founder and current board member of the Urgent Care Assurance Company, a malpractice company specializing in urgent care. He is the founding President of the California Urgent Care Association. He is also the founding president of the South Yuba River Citizens League and served on SYRCL’s Board of Directors for 30 years.