Heart attacks and heart problems increase during the winter all over the world. Yet the incidence varies by area: higher heart attack rates occur more in temperate climates than in colder ones. Summer is also a threat. Studies have found that hot weather is risky for poor people without central air conditioning living in U.S. cities. Being over 65 and/or having diabetes, high blood pressure or heart or lung disease also increases the risk of dying from temperature extremes or from shifts in barometric pressure. High temperatures tax the heart, which has to work harder to keep the body cool; in cold weather, blood pressure is likely to be higher.
Viruses cause these ills, but it’s tempting to blame winter weather. Experiments have shown that people catch cold only when exposed to viruses, not when they are merely chilled. Dry nasal passages resulting from dry winter air might make a person more susceptible. The main reason cold weather and colds go together is probably that winter is school season. Children, who are immune to fewer cold viruses than adults, congregate in schools and daycare centers all winter and spread colds. Still, to many people this has never seemed a sufficient explanation.
People who get migraines often blame the weather, especially changes in weather, but most research has not borne this out. A study published in Headache in 2004 reported that, in some people, weather variables do seem to trigger headaches, but that “more people thought weather was a trigger than was the case.”
Most people with arthritis believe that joint pain comes on in cold, damp weather. In fact, many look on arthritis pain as a dependable barometer. But scientists have never been able to find a connection. An article in Spine reviewed data from 23 centers in the U.S. involving 27,000 people. The only weather variable that appeared to influence physical pain was barometric pressure. However, its influence, researchers said, was minimal. Arthritis pain gets better and then worse, and it’s tempting to link these ups and downs to changing weather. But this is probably a mistake. Moving to a sunny dry climate simply may make you happier.
Weather is a powerful force. It can cause food shortages and heat stroke; it can encourage the breeding of mosquitoes and the multiplication of microbes; it can affect mood for better or worse; it can destroy cities or temporarily shut them down. It can kill. But so far as we can tell, it is not directly to blame for colds, headaches, joint pain or even most heart attacks. Still, researchers will continue to investigate what role it does play in health.