The dog days of August are here, and we should all be on high alert for heat illness. This summer has been characterized by extreme heat and humidity -- two weather patterns that can equal a recipe for disaster. Heat illness occurs when body temperature exceeds a person's ability to dissipate that heat and is commonly diagnosed when the body temperature approaches 104 degrees Fahrenheit and when humidity is greater than 70 percent. Once the humidity is that high, sweating becomes less effective at dispersing body heat, and the core body temperature begins to rise.
Who is at Greatest Risk?
Heat illness is characterized by loss of sweating, confusion leading to coma, fast pulse, low blood pressure, heart failure and kidney failure. Here's the kicker: Patients themselves are often unable to notice these bodily changes, so it's important that friends and family members be alert for the symptoms. Prevention and treatment are critical. Anyone can develop heat illness, but there are some groups of people at increased risk. These include:
- Infants. The very young have a high surface area to mass ratio and readily absorb heat from the environment.
- Athletes. When beginning summer training schedules for outdoor activities such as soccer and football, teenage athletes are very prone to heat illness.
- The elderly. Older adults frequently have heart disease, take medication that can lead to dehydration, and may live in enclosed environments that are not cooled. These are all factors placing them at increased risk.
- People who are obese. Being overweight places people at increased risk of developing heat illness because the extra weight places greater stress on the body's organs.
- Heavy drinkers. Those who abuse alcohol are at increased risk because alcohol is a diuretic and can lead to dehydration.
What Happens to the Kidneys When Someone Has Heat Illness?
Body temperatures above 104 degrees Fahrenheit can cause significant problems for the kidneys. Dehydration leads to low blood pressure and decreased kidney function. Many metabolic systems start to shut down in response to heat illness, and a decline in kidney function is part of that abnormality in metabolic systems. There is breakdown of muscle tissue that results in kidney failure. Finally, heart failure and shock can lead to kidney failure during episodes of severe heat stroke.
What if I Suspect Heat Illness?
If someone you know is warm and confused or delirious, not making any urine and breathing rapidly, it's critical to move them a cooler environment. You should activate emergency services so that this person can be evaluated and transported to an emergency facility. If you have access to a fan, ice or cooling mist, try to use these to cool the patient. For example, applying ice packs to the head and neck, removing layers of clothing and applying cool compresses can all be effective. If the patient is unconscious or poorly responsive, do not offer them oral liquids for fear of inducing aspiration and pneumonia. An ice bath may occasionally be used in the most extreme circumstance, but getting the patient to emergency services is the most important. It is best to call emergency services to assist with someone having difficulty with breathing.
5 Simple Tips to Prevent Heat Illness, From the National Kidney Foundation
- Check the car. Never leave kids or pets in a closed automobile or closed space in a heated environment for any period of time. Children often have no way to remove themselves from warm environments, so if they are left unattended in a car or enclosed area without cooling, their body temperatures can rise to dangerous levels very quickly. This is one of the leading causes of death in children (and pets) in the summertime.
- Skip the booze. Avoid alcohol and diuretics. These cause you to lose water by making you pee more frequently. Instead, stay well-hydrated with plenty of water-based, caffeine-free liquids and ice to stay cool.
- Feel the breeze. No air-conditioning? Open windows and install fans. Find a cooling shelter if necessary.
- Avoid certain drugs. Using non-steroidal anti-inflammatory drugs (NSAIDs) such as Motrin, Ibuprofen, Advil, or Aleve during exposure to heated environments can lead to acute kidney failure.
- Keep an eye on the elderly. Check on elderly friends and relatives frequently and if possible make sure they have access to cooling measures. A mist bottle with a fan can be very effective. In extreme heat, seek out cooling shelters. The elderly often remain in closed heated environments for safety and security reasons, but this places them at high risk for heat illness.
How do you beat the heat? Please share your tips in the comments below.
For more information on kidneys and kidney disease, visit the National Kidney Foundation at www.kidney.org.
For more by Leslie Spry, M.D., FACP, click here.
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