Unless you’ve been living under a rock—hopefully a heated rock, covered by several layers of blankets—then you are probably aware that sub-zero temperatures have overtaken Michigan and much of the Midwest. This isn’t the first time Michigan has seen some cold weather, to be sure, but these have been an extreme couple of days (in particular, after a relatively mild start to the year). The sudden drop in temperature is due to changes in the Earth’s northern polar vortex (there are omnipresent vortices over each of the earth’s two poles); this stratospheric polar vortex can fragment and push the arctic cold farther south into the United States and Eurasia. Each time this happens—and research suggests that it may be happening more frequently and persistently—you’d better hope you have your hats, scarves, and mittens on hand (or head, or neck, as the case may be).

The frigid weather prompted Governor Gretchen Whitmer to declare a state of emergency to “address threats to public health and safety related to…sub-zero temperatures.” This declaration puts the state at the ready to help local governments respond to emergencies. Neighboring states have also issued emergency declarations, due to the life-threatening conditions that have led to multiple deaths. The weather is also placing a strain on infrastructure, causing potholes and water main breaks, and straining the energy supply.

We’re a hardy people here in Michigan: we’re used to dealing with cold winters while scarcely uttering so much as an “ope” in protest. While we all recognize that the current weather is especially nasty and uncomfortable, it’s also important for us to recognize that the cold can have serious health consequences—particularly if we get caught unprepared.

Winter is always cold in Michigan: why a public health emergency?

Low temperatures create numerous threats to the health and safety of individuals and communities, particularly when changes in temperature are sudden and/or in excess of usual weather conditions. Individuals may quickly develop frostbite that can sometimes cause permanent tissue damage and require amputation. Prolonged exposure to cold temperatures can lead to hypothermia—a dangerous lowering of the body’s temperature that requires immediate medical attention. Additionally, because hypothermia affects cognitive function, a person may not recognize its onset and take needed action. Cold temperatures also increase blood pressure, and physical exertion in the cold (like shoveling snow) can lead to a heart attack for those at risk. Since many are apt to discount the dangers posed by extreme cold, public notifications, alerts, and education are important to ensure that people have the information necessary to protect and maintain their health.

Beyond the health effects of exposure to cold temperatures, snow, wind, and icy road conditions carry their own well-known traffic hazards. Slip and fall accidents are certainly also possible when conditions are icy. Road salt and other deicing substances lose effectiveness in extreme cold. The common use of salt, while reducing our risk of traffic accidents, also has some drawbacks that feed back into the stream of public health threats: salting roads corrodes infrastructure (that is already in grave need of better maintenance), and leads to  ecological consequences like water contamination and human health impacts. Road salt can also affect wildlife, harming birds and attracting large, salt-seeking mammals to roadways where the risk of motorist collisions is increased.

Supply chain disruptions from cold and storms may affect health and safety as well. For instance, fuel supply shortages and heightened consumption can strain the energy grid and constrain natural gas for heating. An explosion and fire at a single natural-gas storage and delivery facility in southeast Michigan — combined with above average consumption — caused a major utility to issue warnings that failure to conserve energy during this cold snap could lead to heating interruptions; this emergency plea reportedly led to a 10 percent reduction in gas usage overnight, in spite of the extreme temperatures. Losing home energy and/or heat during the cold can obviously create serious risks for both a house and its occupants.

In our 2018 report “An Ounce of Prevention: What Public Health Means for Michigan,” the Citizens Research Council discussed how social factors (such as income, education level, familial support, and social capital) are central determinants of a person’s health. Social factors also lead to differential risks when it comes to extreme weather—cold that is a trivial inconvenience to some can cause harm to those the more vulnerable. Hypothermia most often affects older adults, babies, and people lacking adequate clothing and shelter, as well as those who use alcohol or illicit drugs. If individuals lack the necessary physical and monetary resources, they will be exposed to much greater risk of injury, illness and death during extreme cold. For vulnerable individuals, public systems for emergency response and preparedness are essential.

Social support systems are equally important. Beyond the direct, heightened risk of hypothermia, the elderly may face greater susceptibility to injury in extreme winter conditions and may be unable to attend to household activities (e.g., shoveling) or to access medical or pharmaceutical care without help from others. The risk to the homeless population from extreme cold is clear and devastating, in particular when resources are limited and need is great.

Although our present cold is a short-term problem (it will be warm again in a few days!), it is part of a long-term trend: The scientific consensus is that human-caused climate change will continue to affect the frequency and severity of extreme weather phenomena and bring about a slew of other public health challenges. Some research has found that frequent Northern Hemisphere mid-latitude incursions by lobes of the polar vortex appear to be a side effect of climate change, but it is difficult to fully understand the complex sets of natural and human-caused changes that interact with one another and lead to this phenomenon. While there may not be scientific consensus on the role climate change plays in a shifting and fragmenting polar vortex, there is clear consensus on the need for governments to prepare for the inevitable consequences of a changing climate and to be ready to respond to occurrences of extreme weather.

Governor Whitmer’s administration and other state leaders are responding to the extreme cold in ways that are necessary to keep people safe. That a brief cold spell (however extreme) can tax Michigan’s infrastructure and resources so severely, however, is indicative of the need for greater investment in our aging infrastructure, as well as public health capacity and systems. Our aforementioned 2018 report on public health recommended greater investment in local public health capacity, as well as admonishing the importance of the government’s role in safeguarding environmental health and facilitating emergency preparedness. Michigan is fortunate to be one of 16 states receiving funds from the CDC to prepare for and respond to the health effects of climate change. Continued state-level investment and support will be necessary to ensure these efforts are sufficient so that we can all be prepared for whatever Mother Nature has in store.