This is your body on heat: How summer weather can lead to organ failure, death

When temperatures in Spokane reach 95 degrees, it’s not just the scorching conditions and brutal sun that make Dr. Rob Lichfield start to sweat. He knows his job as the division lead physician at Providence urgent care is about to be busy.

During heat waves like the one at its peak shrouding the Western United States, Lichfield said he treats a sharp uptick in patients with heat-related ailments such as heat exhaustion or heatstroke.

“This next 10, 12 days looks rough by Spokane standards,” Lichfield said.

During a typical temperate summer stretch, Lichfield estimates he sees a patient with dire heat needs once every two or three days. In heat spells, it’s five times a day.

Some visit in an abundance of caution feeling symptoms creep in; some are less dire, but visit to escape the oppressive sun; some come on the verge of stroke, he said.

In Spokane’s 2021 heat wave, 20 people died from heat exposure, according to the county medical examiner’s report from that year. Most were older people who died in their homes.

The conditions exist on a spectrum of heat afflictions, said Dr. Mohit Jain, an interventional cardiologist who works in the Pulse Heart Institute at MultiCare Deaconess hospital. Heat exhaustion is more common than heat stroke and can lead to heat stroke, which is a more serious medical emergency that presents risks to one’s life and organ function. Typically, this process takes hours of heat exposure, depending on the body and how effectively it can adapt to high heat and low hydration.

Young children and older adults are more at risk of severe heat-related maladies, as are unhoused people who are more exposed to the elements.

While the intricacies vary depending on the person and their circumstances, heat afflictions tend to follow a noticeable sequence of events as they progress from dehydration to heatstroke.

The body is working overtime to adapt to the heat. Hydration is the key resource in this adaptation, Lichfield said. With enough water, the body can effectively regulate its internal temperature and keep its organs running smoothly. As the body’s water supply, or “free fluid,” runs dry, the body has a choice to make: try to cool itself or keep the organs working?

In initial phases of heat sickness, it chooses the former.

“You have blood that is getting diverted from the critical organs to the skin, because really that’s the most critical need, is to cool down the body and all cells work at an optimal temperature,” Jain said.

Lichfield recommends people drink at least two cups of water every 20 minutes while under the blazing sun. It may seem excessive, he said, but “you about can’t drink enough water” during heat events.

There is a caveat, though – while the salt people ingest through regular meals and snacking is usually enough to offset all that water, the U.S. Centers for Disease Control and Prevention cautions against drinking more than 48 ounces per hour, as that can dilute the body’s essential electrolytes. Fortified sports drinks are a popular option in the heat because they replenish some of the salts the body loses through sweating and drinking water, but the CDC still warns against drinking them over that threshold.

Lichfield said in his nine years at Providence, he’s had fewer than a dozen cases of over-hydration.

“If we get dehydrated, the effects of the heat start to snowball on us because now the body can’t dissipate heat as well because it doesn’t have enough fluid to give blood supply to our organs and dissipate the heat,” Lichfield said.

Dehydration and perspiration are the first signs of a heat illness, Jain said, leading one to feel thirsty or dizzy.

The body then redirects blood toward the skin in an attempt to cool down. Capillaries near the skin’s surface expand, allowing the small blood vessels to ferry more oxygen and nutrients through the body and diffuse heat, Lichfield said.

An afflicted person’s pulse will then quicken as the heart increases blood flow to cool the body.

“You’re now circulating much more volume, and so that’s probably in that territory of heat exhaustion where you feel dizzy and lightheaded, you may feel nauseous,” Jain said. “If that process continues and you can’t cool down, then you’re now getting into critical organ damage, and so that becomes a heatstroke.”

Often, confusion or disorientation sets in as the body diverts some resources from the brain. An observer may notice this symptom, Lichfield said, especially when they know the person and can tell they’re acting unusually.

“The phrase we use is ‘cognitively slowed,’ meaning if they’re like, ‘Whoa, man, I don’t feel very good,’ and the world’s kind of turning slower for them at that moment, then they might be overheated,” Lichfield said.

At this point, the body may stop perspiring. It essentially gives up trying to cool itself and focuses resources on the most vital organs.

Without cooling mechanisms like perspiration, the body’s core temperature increases rapidly toward 104 degrees, which the Mayo Clinic defines as heatstroke territory. Meanwhile, cells generate heat while carrying out bodily functions, adding to unregulated core body temperature.

Rising body temperatures and a drop in blood pressure are where Lichfield said heat exhaustion turns into stroke, a dangerous situation where organs begin to fail and can rapidly lead to death.

“The blood pressure is what is sending the blood to the organs,” Litchfield said.

This is when Lichfield would call an ambulance for his patient and send them to the emergency room.

The body then begins prioritizing some functions in what Lichfield calls the “autonomic nervous system.”

“The stuff that your body just does by itself and regulating temperature and prioritizing vital systems, your body just does that all on its own, and it is really awesome at it,” Lichfield said. “As long as it has water.”

The body enters “survival mode,” Lichfield said, slowing organ function based on instinctual priority: the brain, heart and lungs take the cake, while endocrine and reproductive systems, for example, aren’t as critical.

“The body’s trying to stay alive for the next 10 minutes,” Lichfield said. “If that’s how you think about it, the organs that aren’t crucial to stay alive in the next 10 minutes, those ones don’t get as much blood supply.”

Loss of consciousness and seizures are often the final stages before one dies from heat stroke.

Before it gets to that point, Lichfield urges people to visit urgent care within about an hour of experiencing symptoms, if they aren’t improved when out of the heat. Treatment varies depending on severity, from sipping water under doctor supervision to IVs with fluids or a cooling saline solution.

“I just feel more comfortable if people are really, really worried – it’s best to just come in,” Lichfield said. “I don’t ever want people to feel bad for coming in.”