Many people associate winter and the cold weather months with illness—with good reason. We have a generally higher risk of catching colds and the flu during the winter months due to spending more time indoors. In addition, there are other health risks such as increased risk of frostbite and even heart attack. However, there are also several ways that the cold weather months can be good for your physical and psychological health. The health benefits of cold weather include better sleep, which can be a physiological advantage in a variety of ways.
The Health Risks of Cold Weather
Many people dread the long, cold, dark months of winter. There are several reasons for this. First, many people become fatigued or even depressed from the lack of light. Second, the cold of winter can pose very real health risks. People are at additional risk of frostbite and other injuries from the cold. In addition, the intense weather of winter can mean staying inside more often. Not only does this put a temporary end to many of our favorite activities, but it also leads to a markedly higher rate of infectious illness such as colds and influenza.
Certain health conditions also appear to worsen in the winter for reasons we don’t entirely understand. For example, blood pressure rises, as does the rate of heart conditions. Cardiovascular syndromes such as heart attack and angina both are more common and also more life-threatening in the cold weather months. Despite efforts to mitigate the risks of cold weather, such as public vaccination against certain strains of influenza, winter is a time when we are simply more likely to be ill.
Could There be Health Benefits of Cold?
Although there are certainly health risks in the cold weather months, there appear to be a few important benefits. First, being cold raises the metabolism, which means the body burns more calories. This appears to happen through the activation of brown fat, a special kind of fat that is meant to keep animals warm. Cold weather also can decrease inflammation, which is why people commonly put ice on injuries.
Ambient light also may have an effect on sleep in the winter. Our bodies do not make melatonin, a crucial hormone for falling and staying asleep, until our retinas stop sensing even minor amounts of light. The cloud cover of winter and much longer nights make it easier for many people to sleep soundly. Once the Christmas lights are turned off for the season, winter nights tend to be long, cold and dark—optimal conditions for sleep.
However, the real benefit to cold weather, according to a recent study, is higher sleep quality. People fall asleep and stay asleep more easily when their body temperature is a few degrees lower than it is during the day. Cold caps, for example, have been found to effectively treat certain types of insomnia. People with sleep apnea also are less affected by cold weather. Because sleep is known to affect one’s health in a variety of ways, the higher quality of sleep in winter months may have a very real physical impact over our lifetimes.
The Relationship Between Temperature and Sleep
How exactly can the cold cause people to sleep better? Body temperature and the circadian rhythm are linked in a variety of ways. First, it is likely that humans evolved to perceive the evening drop in temperature as a biological cue that it would soon be time to sleep, while perceiving the warming as the sun rises as a cue that it is time to wake. Melatonin appears to cause a dip in central body temperature as well.
In addition, there may be an unknown third factor that influences both sleep and body temperature. Regardless of the nature of the connection, the correlation is clear. People fall asleep more quickly when they are slightly chilled than when they are warm. They also sleep more deeply and for a longer time period.
Sleepless in Winter? Ways to Improve Slumber All Year
How can this information on sleep and temperature be used to help you feel more rested? There are a few things you can do. Lower the temperature in your home every evening before bedtime. You should not feel chilled or be shivering; just a few degrees colder should be enough. Second, get more warmth and light during the day when you feel sleepy, preferably natural light or light from a specially designed sun lamp. The combination of warmth and light during waking hours with cold and dark during sleeping hours appears to be crucial to falling and staying asleep.
If winter leaves you feeling like an earlier bedtime or a long afternoon nap, there is no reason to fight it. Sleep is crucial to good health in a variety of ways. Many of the increased health risks of winter can be mitigated to make this season a win-win situation for your emotional and physical health.