What's the matter with waking up early when it's cold?

　　After the temperature dropped sharply, many people found that their biological clocks had quietly changed - they used to sleep until dawn, but now they often wake up at three or four in the morning, tossing and turning, having difficulty falling back to sleep, feeling listless and unable to concentrate during the day. This phenomenon of "waking up early when it's cold" is not an isolated case. Many people are confused: What's wrong with waking up early when it's cold? This is closely related to temperature changes, body function regulation and emotional state. 　　

What's the matter with waking up early when it's cold?

　　1. Temperature stimulation disrupts sleep cycle

　　The human body is extremely sensitive to temperature changes, and early morning is the time of day when the temperature is lower. When the weather is cold, in order to maintain core body temperature, the body will initiate a stress response, causing blood vessels to constrict and metabolism to accelerate, which in turn causes sleep to change from deep to shallow, eventually causing early awakening. Especially when the bedroom is not warm enough, cold hands and feet will directly stimulate the nerves and interrupt the sleep process.

　　2. Hormone secretion fluctuates under the influence of light

　　Melatonin is a key hormone that regulates sleep, and its secretion depends on the "dark environment." When the weather is cold, the days are short and the nights are long. The low light in the early morning can easily penetrate the curtains and stimulate the retina, causing the secretion of melatonin to decrease. The secretion of cortisol, which promotes wakefulness, rises in advance. A drop or rise of cortisol will cause people to wake up prematurely.

　　3. Vasoconstriction causes physical discomfort

　　Low temperature causes blood vessels throughout the body to constrict, causing blood pressure to fluctuate. Middle-aged and elderly people or people with underlying diseases such as hypertension and coronary heart disease have poor blood vessel elasticity. A sudden rise in blood pressure in the early morning can easily cause minor discomforts such as dizziness and chest tightness. These signals will be transmitted to the brain and wake people up from their sleep.

How to improve waking up early in cold weather

　　1. Optimize the bedroom environment and keep warm

　　Control the bedroom temperature at 18-22°C. Use a hot water bottle to warm your feet before going to bed or turn on an electric blanket to preheat your bedding.； Choose thick curtains to block the early morning light, create a dark and warm sleeping environment, and reduce the interference of temperature and light on sleep.

　　2. Adjust daily routine and bedtime habits

　　Set a fixed time for going to bed and getting up every day. Even if you wake up early, don’t stay in bed to avoid disrupting your biological clock.； Stay away from mobile phones and computers one hour before going to bed. You can relax your body and mind by soaking your feet and listening to soft music to avoid emotional excitement.

　　3. Adjust diet and supplement nutrition

　　Avoid overeating or salty dinners, and do not eat 2 hours before going to bed； You can eat millet, walnuts and other sleep-aiding foods in moderation, and eat more foods rich in vitamin D during the day to make up for the nutritional gap caused by insufficient sunlight.

　　Waking up early in cold weather is mostly a "signal" for the body to adapt to the season, rather than a serious illness. Most people can improve this problem by adjusting their environment, routine, and emotions. If you wake up early and are accompanied by persistent dizziness, palpitation or depression, you need to seek medical attention promptly to check for potential health risks.