Extreme Weather Swings from Sunny Highs to Shivering Cold Take a Toll on Your Health

Lily Pien, an allergist at the Cleveland Clinic, recently experienced an unusual weather phenomenon that had her bracing for an influx of patients seeking relief for their suddenly suffering noses. She drove to work earlier this week in snow and hail, only to find the next day that it was 65 degrees and sunny. "My schedule is filled up," she said. "As the weather changes, so does my patient load and their nasal symptoms." Many parts of the United States have seen wild weather swings and unseasonable conditions in recent days. The West is shivering in record cold, while the Southeast and Mid-Atlantic are experiencing unusual heat for February, including a pattern of springlike days on top of cold snaps - and vice versa. This type of weather whiplash can have a significant impact on human health, especially among those with existing medical conditions. According to experts, sudden temperature and humidity changes can affect the nose, making someone more vulnerable to bacterial and viral infections. Lower humidity, for instance, can lead the nose to dry up, "making the nasal tissues more susceptible to possible infection," Pien said. These sudden changes in temperature can also prompt symptoms among those who have allergies - and even among those who don't, including people who suffer from nonallergic rhinitis or allergy symptoms with no identified cause. "The nose is comprised of mostly blood vessels, which constrict when it is cold, and dilate with higher temperatures and more humidity," she said. "When the weather goes back and forth in a 24-hour period, you can go from a runny nose to dry nose rather quickly. Such fluctuations bewilder plants and animals, disturb the balance of delicate ecological systems and can exacerbate human health problems, especially among those with existing medical conditions, experts said. These changes can aggravate allergies, cause infections and worsen other more serious conditions, such as heart disease, they said. "That jolt to your system can bring out all sorts of problems," said Aaron Bernstein, interim director of the Center for Climate, Health, and the Global Environment at Harvard T.H. Chan School of Public Health (Harvard Chan C-CHANGE). "Going from 40 degrees to 80 degrees might not be a big deal for relatively healthy people, but could be for certain people, such as outdoor workers and people with chronic medical problems and other risks." The human body has the ability to acclimate to temperature change, "but it doesn't kick in within a span of a few hours," he said. "It takes many days - up to two weeks - to get acclimated Gaurab Basu, co-director of the Center for Health Equity Education & Advocacy at the Cambridge Health Alliance, agreed. "Our bodies are a delicate equilibrium and working hard to maintain a certain body temperature," he said. "They have to find ways to compensate for extremes." These sudden changes in temperature can also be bad for the heart. Heat causes stress in the body and stress hormones can strain the heart, Bernstein said. Cold can cause hypothermia and lead to thicker blood that is "more prone to creating blood clots, leading to strokes, heart attacks and clots in the extremities," he said. A study in May in the Lancet Planetary Health journal found that over time these abrupt temperature shifts are associated with increased mortality. Deaths related to these sudden jumps partly depends on the previous day's temperature, Bernstein said. "It's probably worse if you go from a relatively cooler temperature of 60 degrees to 95 degrees than if you had been in the 80s the day before and went to 95," he said.