Photo by Ryan Stone on Unsplash.

With high temperatures beginning to show up all around the country, it’s time to get prepared for dealing with extreme heat. Fortunately, there are some new resources that can help with that and some new understanding of what constitutes risk that can help you calculate what is safe and what isn’t as the mercury rises.

As climate change progresses, it’s important that people living in areas historically unaffected by extreme heat realize that they likely no longer get a pass, and for those living in areas accustomed to dangerously high temperatures, it is now necessary to prepare for longer and more persistent heat waves that will potentially take a bigger toll on health.

HeatRisk Tool

The forecast is more nuanced than simple temperature and humidity readings.

One new resource is a forecast tool put out by the National Weather Service called HeatRisk. When you navigate to this website, you will see an interactive map of the US that is color-coded by expected risk and allows you to look forward for seven days to see how your area is likely to be affected.

The forecast is more nuanced than simple temperature and humidity readings, as explained by Centers for Disease Control environmental health scientist Aaron Bernstein. “A hundred degrees in Boston is different from one hundred degrees in Houston when it comes to how it affects health,” he says. New England residents are less likely to have air conditioning in their homes and don’t expect to have to curtail their outdoor activities, whereas those in Houston are well versed in how to guard against heat-related illness.

Another advantage of the HeatRisk tool is that you can look ahead for seven days, allowing more time to be prepared or to make appropriate plans and precautions. Previously, warnings of extreme heat came as little as 12 hours before the sweltering began.

There are not enough humidity gauges nationwide to provide accuracy on its map.

Given that humidity is another risk factor in hot weather, the CDC had to jump through a few hoops to overcome the fact that there are not enough humidity gauges nationwide to provide accuracy on its map. Instead, the difference between daily high and low temperatures–greater when there is less humidity–was substituted for direct humidity readings.

Further figuring into the map’s accuracy are several other measurements: elevated nighttime temperatures, which typically prevent the body from cooling adequately, whether the duration of high temperatures is more than a couple days, and whether the expected highs are at or above the top five percent of record temps on any given days.

If you tab over from the map on the front page of the website you will find much valuable information about heat-related risk and how to respond to it, as well as a list of online resources if you want to dig deeper into the CDC’s guidance for dealing with heat.

We here in California are all too familiar with the experience of air quality issues in tandem with high temperatures, most often caused by smoke from wildfires, nearby or blown in by winds from far away, further aggravating risk to health. The CDC has launched another website that allows you to input your zip code to get a risk factor based on combined temperature and air quality. This is a good one to have bookmarked as fire season has already begun.

Recognizing and Responding to Heat-Related Illness

Get into a cool dry place, sip water, and apply cool, damp cloths to the body.

The negative effects of too much heat range from dehydration to heat exhaustion, and most dangerously, to heat stroke, which can be fatal. If you start to feel unwell, develop muscle cramps, or a heat rash consisting of patches of raised pimple-like blisters, get out of the sun, drink water, and do not resume activity until you feel completely recovered and are adequately hydrated. If the cramps do not subside you may need medical attention.

It is advisable to err on the side of caution, especially if you are unaccustomed to heat, or have little experience knowing how it affects you.

Heat exhaustion is characterized by stronger symptoms such as nausea or vomiting, cold, clammy skin, dizziness, headache, fainting, and sometimes a fast, weak pulse. Get into a cool dry place, sip water, and apply cool, damp cloths to the body. Get medical attention if the vomiting persists, other symptoms worsen, or you do not feel better after an hour of trying to cool down.

Heat stroke is a medical emergency, characterized by a core body temperature elevated to 103 degrees or higher, hot skin, dizziness or confusion, fast strong pulse and possibly passing out. Call 911 immediately and get into a cool dry place or get to an emergency room as fast as possible. Do not drink anything, but do take a cool bath or apply cool damp cloths. Ice packs should be put on the armpits, groin, neck, and head. Heat stroke happens when the core temperature can no longer be self-regulated. Recovery can take months and there may be permanent organ damage. The likelihood of serious complications increases the longer it takes to get care.

The Human Toll of Heat-Related Illness

In 2023, heat-related illness caused 2300 deaths in the US. Jane Gilbert, chief heat officer in Dade County, Florida, believes that to be a large underestimation as deaths from kidney disease and heart attack are much more common during heat waves, but heat is not named as the official cause. (Where have we heard this before?) Other heat-related causes of death or severe illness are attributable to the symptoms of confusion. Mental health issues such as mood disorders and anxiety can be exacerbated, causing poor judgment. Pregnant women should be especially cautious.

During a devastating heat wave in Europe in 2022, 61,000 people died. While the numbers sharply increase with advanced age, 20% of heat deaths occur in the healthiest age-span of 15-40 years. Heat illness does not care how old you are.

It’s not a sign of fitness or grit to keep going after throwing up or feeling light-headed when working or exercising outside on a hot day. Take a break, get into the shade, hydrate, and rest. Check on your neighbors and family when in doubt.  Friends don’t let friends overheat.

Ann Constantino, submitted on behalf of the SoHum Health’s Outreach department.