Summer brings lots of sunshine and fun, but the high temperatures and sweltering humidity can spell disaster if you're not prepared.
Two emergency medicine experts from The University of Texas Health Science Center at Houston (UTHealth) share some of the most common heat-related illnesses they treat, as well as tips to avoid landing in the emergency room this summer.
Heat exhaustion
Heat exhaustion can occur when the body is not able to properly cool itself in hot weather and starts to overheat.
Heat exhaustion is the most common heat-related illness we see in the emergency room. It's not just people who are new to hot conditions that are affected. Awareness of the heat can actually lull you into a false sense of security. We end up treating a lot of people who think they are acclimated to the high temperatures, but heat stress can be a lot more powerful than they realize."
Henry Wang, MD, professor in the Department of Emergency Medicine at McGovern Medical School at UTHealth, who also sees patients at Memorial Hermann-Texas Medical Center
Sweating is the body's cooling mechanism. If the body depletes its reserve of salts and fluids, but is still exposed to high temperatures, heat exhaustion can occur.
"The evaporation of the sweat pulls heat off the body and regulates its temperature," Wang said. "However, in humid climates, sweating is not as effective as it is in dry climates due to the increased moisture in the air. If you notice that you have stopped sweating while you are out in the heat, this may be a late sign of heat exhaustion and it would be best to take a break and rehydrate."
Usually, the beginning signs of heat exhaustion are feeling hot, dizzy, lightheaded, or nauseated. Other symptoms include headaches; cramps; strong pulse; fainting; hot, red, and dry skin; excessive sweating; and a lack of sweating, which is a late symptom that signals the depletion of the body's fluid and salt reserve.
Heatstroke
Heat exhaustion left unchecked can lead to heatstroke, which can occur when the body's core temperature reaches 104-106 degrees Fahrenheit or higher.
"As the body temperature goes up, the heart begins to fail, fluid in the lungs starts to back up, and the body starts to makes lactic acid, putting the organs, especially the kidneys, at risk. The body can go into a coma, which could result in brain damage and sometimes even death," Wang said.
When heat exhaustion starts to move toward heatstroke, the central nervous system begins to shut down, which can lead to symptoms of confusion, hallucinations, coma, seizures, and/or disorientation.
According to the Centers for Disease Control and Prevention (CDC), 334 people die per year from heatstroke in the U.S.
There are two types of heatstroke: exertional and non-exertional. Exertional heatstroke occurs in young people who are generally healthy, but who may not be acclimated to the heat while being active outdoors. Non-exertional heatstroke predominantly affects the more vulnerable populations, including older people, the chronically ill, children, and infants.
When the temperature is at or above 90 degrees, everyone should take precautions against heatstroke. However, heatstroke can happen anytime, depending on your body temperature relative to the conditions outside.
"It can be 80 degrees and humid and if you're exercising, your body can become overly stressed," Wang said. "Always listen to your body and stay vigilant."
Hot car deaths
Spending time in a hot car puts the body at risk of heatstroke, especially for young children.
According to the safety organization Kids and Cars, on average 38 children in the U.S. die each year from heatstroke after being left in a vehicle. Texas and Florida have had the most hot car deaths involving children age 14 and under, with Texas recording 125 fatalities since 1990.
In Houston alone, about one or two kids pass away tragically each year from spending too much time in a hot car. It's never acceptable, in any circumstance, to leave children in a car that is turned off, even if you crack the windows."
Samuel Prater, MD, assistant professor in the Department of Emergency Medicine at McGovern Medical School and the medical director of Memorial Hermann-TMC's Emergency Department
Even with windows left slightly open, the temperature inside the car can increase by 20 degrees in just 10 minutes.
"Even if it is only 57 degrees outside, heatstroke can occur, so parents must be vigilant when traveling with their children in tow. They also must keep an eye on their kids at all times while at home, as 30 percent of heatstroke deaths happen because the child got in the car without the caregiver knowing," Wang said.
Some tips to avoid leaving children in a hot car:
- Don't leave car keys in places that are easily accessible to children
- Teach children that the car is not a safe place to play
- Keep fold-down seats closed to prevent kids from climbing in the trunk
- When transporting a child, put something you need in the backseat, like a purse, briefcase, backpack, or shoe
- Utilize apps and new technology that use sensors to alert parents or caregivers that a child is still in the car
Dehydration
Dehydration – when your body doesn't have as much water as it needs – can happen very quickly in high temperatures as the body increases its sweat production.
Signs of dehydration include thirst, dry mouth, dark yellow urine, dry and cool skin, headache, and muscle cramps.
Make sure to stay hydrated with any kind of liquid except for drinks filled with sugar or alcohol. Sports drinks or Pedialyte, something with salt and minerals included, are best."
Samuel Prater, MD
Wang notes that drinking an excess of just plain water can actually dilute your salt level, which can cause confusion, seizures, and death.
"If you start to become dehydrated, remove any warm or bulky clothing and get air and cold water on the body as fast as you can," Wang said. "This can be done using fans, wet towels, or even immersing your feet and hands in cold water. Taking these proactive steps can help prevent dehydration from turning into full-blown heat exhaustion and heatstroke."
Advice for anyone planning to spend time outdoors
- Make sure you have access to shade
- Stay hydrated with sports drinks and water
- Pace yourself
- Wear sunscreen of sun protection factor (SPF) 15 or higher
- Dress in lightweight, light-colored clothing
- Eat regular meals
Additional advice for outdoor workers
- Pay attention to your body and take breaks when necessary
- Consider wearing lightweight clothing with SPF
- Stay in shape
- Acclimate your body before working in hot conditions
- According to the CDC, heat acclimation is the improvement in heat tolerance that comes from gradually increasing the intensity or duration of work time in hot conditions
- Best results come from increasing exposure over a period of seven to 14 days, cooling off and fully rehydrating between shifts
- Typically, acclimation requires at least two hours of heat exposure per day
- To fully acclimate, the same work that will be performed must be done during the acclimatization period
- Acclimation will be maintained for a few days after heat exposure stops, but will begin to be lost after about a week
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