My last article focused on the best way to measure heat discomfort, comparing dew point and relative humidity. Let’s go past the comfort issue and move on to heat illness.
Nationally, heat is one of the leading weather-related killers, with hundreds of victims annually. Fortunately, Western New York experiences fewer episodes of dangerous heat than most other parts of the country, but we are far from immune. When you factor in the neglect that leads to tragedies for pets and small children left in cars, the greenhouse environment of our vehicles is extremely significant. More on that later.
As far as National Weather Service heat criteria, the lowest level of alert is a heat advisory, issued within 12 hours of the onset of what the National Weather Service calls “extremely dangerous heat conditions.” The weather service relies upon the heat index, which factors in moisture in the air with the temperature. It also includes the stress that is worsened by nighttime heat and humidity, in which overnight lows are expected to remain higher than 75 degrees with high humidity. That can really take a toll in homes with no air conditioning, especially for the elderly, infants and those with chronic heart or lung disease.
We are, at least, much less likely to see an excessive heat watch or excessive heat warning in our region, when is issued when a prolonged heat index of 105 or higher is expected. Such conditions present a truly widespread danger to the general population. A 1995 heat wave in Chicago caused 739 deaths over five days. Peer-reviewed data shows a 2003 heat wave across Europe killed 70,000 people. Much of Europe did not have air conditioned homes or businesses at the time, and only minor incremental improvement has occurred since despite that monumental catastrophe.
A heat wave is generally said to be occurring if a period of excessive heat and humidity persists for two days or longer. That’s when the health impacts from the heat really begin to multiply.
The least critical stage of heat illness is the presence of heat cramps. The cramps are usually preceded by unusually heavy sweating during exercise. The Centers for Disease Control and Prevention and other medical experts recommend what may seem obvious: Get out of the sun to a cooler spot, drink lots of water or water with electrolytes, and rest until all cramps have gone away. If you’re on a low-sodium diet, you may need medical attention. Salt tablets are no longer recommended.
The next step up is heat exhaustion, and it is more dangerous. The CDC lists the presence of cool, clammy skin despite profuse sweating, weakness, headache, dizziness, nausea or vomiting, fainting, cramps, and a fast, weak pulse. Cooling the body is critical and can be accomplished by applying cool, wet cloths; taking a cool bath; and sipping cool water. Medical attention is recommended if vomiting continues and other symptoms worsen, especially if symptoms persist more than an hour.
The most critically dangerous stage of heat illness is heat stroke. This is evident with a body temperature of 103 degrees or higher; hot, red skin (damp or dry); a fast, strong pulse; headache; nausea; dizziness; confusion; or passing out. The first step to take in the presence of these symptoms is to dial 911 and move the victim to a cooler place while waiting for help. Cool the victim with cool cloths or a cool bath, but do NOT give water.
Heat stroke is absolutely a matter of life or death. Again, here is the CDC checklist.
Finally, we return to one of the most frequent danger zones for serious heat illness: our vehicles. The threat is illustrated in an experiment the National Weather Service La Crosse forecast office conducted on a hot Wisconsin day, not dissimilar to a hot day around here. With outdoor temps in the low to mid-90s, they parked a car in the sun with closed windows after cooling the interior with air conditioning to 82. Within a bit more than two hours, the car interior temperature had risen to 124 degrees. Even after opening the car windows with a good breeze blowing, the interior only dropped to 112 degrees.
Infant body temperatures rise faster than those of adults. As for our pets, the American Veterinary Medical Association provided these disturbing measurements. Note the first column, with an outside temperature of only 70 degrees,
Wearing light colors with thin, breathable fabrics can help keep you quite a bit cooler if you have to be in the sun. So, even if you’re built like Orson Welles in his later years, pass on the black outfits, folks. Vanity has to give way to sanity.
In general, infants, the elderly, the chronically ill and our pets are at greatest risk to excess heat. It’s an understatement to say we need to pay more attention when we’re transporting children and pets in our cars and trucks when parking.
Indoors, despite heat and humidity, fans generally do offer at least a little additional evaporational cooling from the skin. “Fans just blow the hot air around” is true enough, but if conditions aren’t extreme, the extra ventilation may forestall the worst effects of the heat.
As for you lean, healthy runners, the sense of near-invulnerability some of you seem to possess can get you in trouble. When I was young, quite fit and a regular runner, I worked for a year at a Tampa TV station. I interviewed Dr. Robert Cade, a University of Florida professor and physician. Cade invented Gatorade. I told him I often ran in the heat of the day. He told me that was really dumb … words to live by.