Summer is here and the Midwest and East is experiencing record high temperatures in a major heat wave. Officials predicted a high-risk situation as the heat index surpasses heat indexes in 90s and 100s, and in some case, the 110s. Close to 200 million people might be affected in 32 states, according to the U.S. weather service.
The “heat index”, by the way, is a measure of the effects of air temperature combined with high humidity. Above 60% relative humidity, loss of heat by perspiration is impaired exposure to full sun increases the reported heat index by as much as 10-15 degrees F. All this increases the chances of heat-related illness.
We can expect the power grid to be challenged by tens of millions of air conditioning units set on “high”, and we can expect to see some major health issues if the electricity goes out and people have to fight the heat with hand fans, like they did in the “good old days”.
You might not consider a heat wave to
be a natural disaster, but it most certainly is. Heat waves can cause mass
casualties, as it did in Europe when tens of thousands died of exposure (not in
the Middle Ages, but in 2003). They’ve already experienced one bad one this
year and are predicted to have another in the near future. India, Pakistan, and
other underdeveloped tropical countries experience thousands of heat-related
So how exactly does heat kill a person?
Your body core regulates its temperature for optimal organ function. When core
body temperature rises excessively (known as “hyperthermia”), toxins leak, inflammation
occurs, and cells die. Fatalities can occur very quickly without intervention,
even in those who are physically fit. Even in modern times, hyperthermia
carries a 10% death rate, mostly in the elderly and infirm.
The ill effects due to overheating are called “heat exhaustion” if mild to moderate; if severe, these effects are referred to as “heat stroke”. Heat exhaustion usually does not result in permanent damage, but heat stroke does; indeed, it can permanently disable or even kill its victim. It’s a medical emergency that must be diagnosed and treated promptly.
muscle cramps or a fainting spell doesn’t necessarily signify a major
heat-related medical event. You will see “heat cramps” often in children that
have been running around on a hot day.
Getting them out of the sun, massaging the affected muscles, and
providing hydration will usually resolve the problem.
In addition to
muscle cramps and fainting, heat exhaustion is characterized by:
Nausea and Vomiting
Temperature elevation up to 105 degrees F
If no action is
taken to cool the victim, they could easily go on to heat stroke. In addition
to all the possible signs and symptoms of heat exhaustion, heat stroke will
manifest as loss of consciousness, seizures or even bleeding (seen in the urine
or vomit). Breathing becomes rapid and shallow.
If not dealt with
quickly, shock and organ malfunction may ensue, possibly leading to death. In
heat stroke, the skin is likely to be red and hot to the touch, but dry; sweating
might be absent. Once the body core hits
105 degrees or more, thermoregulation breaks down and the body’s ability to use
sweating as a natural temperature regulator fails. In heat stroke, the body
core can rise to 110 degrees Fahrenheit or more.
circumstances, the patient’s skin may actually seem cool. It is important to realize that it is the
body core temperature that is
elevated. A person in shock may feel “cold and clammy” to the touch. You
could be misled by this finding, but simply taking a reading with a thermometer
will reveal the patient’s true status.
When overheated patients are no longer able to cool themselves, it is up to their rescuers to do the job. If hyperthermia is suspected, the victim should immediately:
Be removed from the heat source (for example, out of the sun).
Have their clothing removed.
Be drenched with cool water (or ice, if available)
Have their legs elevated above the level of their heart (the shock position)
Be fanned or otherwise ventilated to help with heat evaporation
Have moist cold compresses placed in the neck, armpit and groin areas
Why the neck, armpit and groin? Major blood vessels pass close to the skin in these areas, and cold packs will more efficiently cool the body core. Recent studies by the military suggest that cold packs to feet and hands are also helpful.
rehydration is useful to replace fluids lost, but only if the patient is awake and alert. If your patient has altered
mental status, he or she might “swallow” the fluid into their airways; this
causes damage to the lungs and puts you in worse shape than when you started.
Heat stroke is preventable in many cases. People that should know about hot weather, the Arizona department of health, recommends the following:
Drink at least 2 liters (about a half-gallon) of water per day if you are mostly indoors and 1 to 2 additional liters for every hour of outdoor time. Drink before you feel thirsty, and avoid alcohol and caffeine.
Wear lightweight, light-colored clothing and use a sun hat or an umbrella to deflect the sun’s rays.
Eat smaller, more frequent meals instead of large ones.
Avoid strenuous activity.
Stay indoors as much as possible.
Take regular breaks if you exert yourself on warm days.
In a heat wave, it’s important to check on the elderly, the very young, and the infirm regularly and often. These people have more difficulty seeking help, and you might just save a life if you’re vigilant. You can bet there’ll be more than one heat wave this summer, so know the warning signs and how to help those with hyperthermia.