Tornadoes, hurricanes, floods, lightning...these are often the types of deadly severe weather that make headlines. Surprisingly, over the 30-year average from 1987-2016, excessive heat caused more fatalities per year, than any of these aforementioned types of hazardous weather. The threat from heat is multifaceted: whether from the combination of heat and humidity, the dangers of hot car interiors, or simply not being aware of the symptoms of heat-related illnesses, education is the first step to ensuring you “beat the heat” this season.
Weather Fatality Statistics - Source: NOAA (NWS)
In General, When Does Heat Become Dangerous?
Outside of the specific example of an enclosed space, like a car or other automobile, heat becomes dangerous when the temperature and/or heat index is high enough to warrant a Heat Advisory or an Excessive Heat Warning from the National Weather Service. The heat index is the apparent temperature, or how hot it “feels” when humidity is factored in. While there is some variability for different parts of the country, most NWS offices will issue a Heat Advisory when the heat index will be at least 105°F for less than 3 hours per day or if nighttime low temperatures don't dip below 80°F for two consecutive days. If the heat index stays above 105°F for more than 3 hours on two consecutive days, or if it reaches 115°F for any length of time, then an Excessive Heat Warning will be issued.
Heat Index Chart - Source: NOAA (NWS)
What About Heat Inside Cars?
Car interiors are especially dangerous, as far as heat-related fatalities are concerned, because it doesn't have to be very hot outside the car for temperatures to reach life-threatening levels inside. In an alarming 2005 study by the American Academy of Pediatrics, even at outside temperatures of only 72°F on a bright, sunny day, in-car temperatures can reach 117°F within 60 minutes, with 80% of the temperature rise occurring in the first 30 minutes. This same study also found that “cracking” a window open an inch or two made little difference to the heat rise within the car. The bottom line is, never leave a child unattended in a parked car. The same advice applies for pets, as well.
Temperature Rise In-Car for "Cracked" vs. Closed Windows - Source: American Academy of Pediatrics
How Can I Recognize Heat-Related Illnesses? What Do I Do?
The first symptom of heat-related illness can sometimes be heat cramps. The painful muscle cramps or spasms usually develop in the legs or abdomen, and can also be accompanied by heavy sweating. The CDC recommends applying firm pressure on the cramping muscles and/or gently messaging them. Also make sure the person takes sips of water, unless nausea is also a symptom, then avoid giving water right away.
The first type of heat-related illness is heat exhaustion, which can be recognized by a number of different symptoms including: heavy sweating, weakness, pale/clammy skin, fast/weak pulse, possible muscle cramps, dizziness, nausea or vomiting, and fainting. If one or more of these symptoms develop, immediately move the person to a cooler environment (whether air-conditioned or near a fan), lay or have the person lie down and loosen their clothing. If available, apply cool, wet cloths to as much of the body as possible, and hydrate slowly by offering sips of water if the person is well enough to drink. If vomiting occurs more than once, seek immediate medical attention.
The second and most serious type of heat-related illness is heat stroke. Heat stroke is characterized by a body temperature above 103°F and often exhibits symptoms like: altered mental state, dizziness, nausea, shallow breathing, confusion, headache, hot/red/dry skin, rapid/strong pulse, fainting, and loss of consciousness. If heat stroke is suspected, it should always be treated as a medical emergency by immediately calling 911, or by taking the victim to a hospital. While awaiting medical attention, the person should also be moved to a cooler, air-conditioned environment. Also, if possible, apply cool cloths or provide a cool bath. However, in cases of heat stroke it is NOT recommended to give the victim fluids, as nausea and/or muscle spasms may make drinking unsafe.
Heat Stroke vs. Heat Exhaustion - Source: National Agricultural Safety Database
Excessive heat is, on average, the leading cause of weather-related fatalities in the United States. Being aware of the types of heat-related advisories that the NWS may issue, knowing the dangers of leaving pets and children unattended in parked cars, and recognizing the signs and symptoms of heat-related illnesses and knowing how to act can go a long way in reducing the number of heat-related deaths. The main tips to “beat the heat” this season, as always, are:
- Limit outdoor activity, especially midday and early afternoon when temperatures are typically hottest
- Stay hydrated - Don't wait until you're thirsty to drink more fluids
- Maximize your time in an air-conditioned environment, whenever possible
- Check on elderly neighbors
