“Wanting to stay in bed when it’s cold” is not laziness, but a life-saving skill passed down by human ancestors?

As the weather gets colder, it seems to be getting harder and harder to get up in the morning. After waking up, I always want to stay in bed for a while. Why do we want to get up less and less when the weather gets colder?

This is not really due to laziness, but rather an advanced life-saving skill left by human ancestors.

It's cold and I want to stay in bed

The body is protecting itself

Light and temperature have an important impact on the rhythm and quality of our sleep. This is because our brain secretes a substance called melatonin, which is like a "sleep switch" that can promote sleep and prolong sleep time.

This "switch" is regulated by light. The morning sun will inhibit the secretion of melatonin, telling the brain that it is daytime and time to get up. In the cold winter, the sun comes out late, and melatonin continues to be secreted, which can easily make people feel sleepy and unable to wake up.

In addition, when the weather is too cold, the quality of sleep will decline. If you want to have a high-quality sleep, the temperature of the microclimate formed between the person and the bed generally needs to be maintained at around 32-34°C. However, in the cold weather in winter, this ideal sleeping environment will be affected to a certain extent, and it is not easy for people to sleep well.

Moreover, when the weather is cold, people like to take a warm bath to warm up their bodies before going to bed, but the overheated temperature inhibits the secretion of melatonin, making it more difficult to fall asleep. If you can't sleep well in cold weather, you will naturally be unable to wake up during the day.

In addition, the awakening process is also affected by the ambient temperature. The core body temperature gradually drops during the process of falling asleep, and when waking up, the core temperature needs to recover slowly. When the weather gets colder, it takes more time for the core body temperature to recover and wake people up from sleep.

To sum up: If you don't want to get up when it's cold, it's not because you're lazy, but because your body is adapting to the environment and needs a longer time to wake up. At this time, you might as well wait patiently for a while before getting up to let your body "turn on" first.

Image source: unplash

It's cold and I want to stay in bed

It is a life-saving skill left by human ancestors.

As a warm-blooded animal, humans have a temperature range that is most suitable for them. A night's sleep makes the temperature inside the quilt warm and comfortable, but it is cold outside the quilt. Being cold means that more energy is needed to maintain body temperature, but if you continue to lie in bed, you can maintain body temperature.

At this time, the energy-saving mechanism engraved in the genes tends to make people choose to stay in a warm bed. This mechanism comes from the experience of our ancestors who lived in caves and were afraid of hunger and cold , that is, to save energy as much as possible and protect the body from the harm of cold.

In addition, when the weather is cold, in order to maintain body temperature, the blood flow slows down, and the limbs are often stiff and inflexible when you wake up in the morning. This discomfort makes people even more reluctant to move.

In addition to the above two points, there is another reason that is often overlooked. As the temperature drops, the body and emotions seem to enter "winter mode". At this time, the brain may suffer from an "emotional cold", that is, seasonal depression.

This is a state of depression, anxiety and fatigue caused by cold weather. It is manifested by often feeling like being wrapped in a heavy quilt during the day, drowsiness, lack of energy and sleepiness, sleeping longer at night, and finding it difficult to get up from the warm bed in the morning.

Stay in bed properly

Can really protect heart and brain health

When the indoor temperature is low, after people curl up in the quilt and fall asleep, their heads and faces will be stimulated by the cold air. This cold stimulation of the face only (cold face test) will increase the activity of the cardiac parasympathetic nerves and induce bradycardia. At this time, if you are quickly awakened from sleep and enter an excited state, the blood vessels will contract rapidly due to stress, and the heart needs to increase the load to maintain blood circulation, which can easily cause dizziness, palpitations, postural hypotension, and even cardiovascular disease. Staying in bed for a while can give the body enough time to adapt to the temperature difference between indoors and outdoors, reducing the burden on the heart and brain.

Doctors also recommend adhering to the "221" principle of getting up when the weather is cold, that is, lie in bed for 2 minutes after opening your eyes, sit for 2 minutes after getting up, sit by the bed and wait for 1 minute before standing up and moving, giving the blood vessels and heart a buffer time.

In addition, a new study from Stockholm University in Sweden found that people who take a nap after the alarm goes off have younger brains. Especially for those who like to stay up late or skip lunch breaks, a proper "snooze" in the morning can improve cognition, reduce fatigue, and make the emotional state more positive.

So, if you struggle to get up in the morning in winter, just listen to your body, stay in bed for a while, and slowly get up! This is a high-level skill left to us by our human ancestors, and it is really good for the body!

References

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[7] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3427038/

[8] Mirzakhani L, Poursafa P. The Association between Depression and Climatic Conditions in the Iran Way to Preventive of Depression. Int J Prev Med. 2014 Aug;5(8):947-51. PMID: 25489441; PMCID: PMC4258674.

[9] Sundelin, T., Landry, S., & Axelsson, J. (2023). Is snoozing losing? Why intermittent morning alarms are used and how they affect sleep, cognition, cortisol, and mood. Journal of Sleep Research, e14054.

Planning and production

Author: Hardy, PhD in Neurobiology, Zhejiang University

Reviewer: Li Jingjing Professor and Chief Physician, Department of Neurology, Beijing Tiantan Hospital

Planning丨Lin Lin

Editor: Lin Lin