High temperatures can disrupt the body temperature regulation mechanism, causing many people to have difficulty sleeping, have light sleep, and wake up many times during the night.
Doctor Hoang Quyet Tien, Medical Information Center, Tam Anh General Hospital, Ho Chi Minh City, said that the more the environmental temperature increases, the more sleep is affected. A study conducted by the University of Copenhagen (Denmark), published in One Earth magazine (2022), analyzed sleep data of more than 47,620 people in 68 countries, showing that high night temperatures cause a person to sleep less and make it difficult to achieve quality sleep, especially the elderly.
Heat hinders the process of hypothermia
To fall asleep, the body's core temperature needs to begin to decrease. This is an important biological signal for the brain to switch from alertness to rest.
On hot days, the body has difficulty radiating heat. Blood vessels under the skin must continuously dilate to release heat, while the surrounding environment is too hot, making this process ineffective. As a result, body temperature remains higher than normal, making it difficult to fall asleep.
High temperatures disrupt melatonin
Melatonin is a hormone secreted by the pineal gland, which plays a role in regulating circadian rhythm, signaling it is time to sleep. Environmental temperatures that are too high can disrupt circadian rhythms, affecting melatonin secretion. When the amount of this hormone decreases or is secreted later than normal, the body will have difficulty falling asleep even when it's time to rest.
Not only that, hot weather also causes the sympathetic system to work harder to regulate body temperature, maintain circulation, and balance water and electrolytes. Therefore, it is difficult for the brain to completely switch to a state of relaxation, causing the patient to not sleep deeply and wake up easily.
Sweating causes restless sleep
One of the most common symptoms in the hot season is sweating a lot while sleeping, causing discomfort and waking up in the middle of the night. Waking up multiple times during the night reduces sleep quality.
Poor sleep quality due to prolonged heat can cause fatigue when waking up, decreased concentration, daytime sleepiness, irritability and reduced work efficiency. Prolonged lack of sleep also increases the activity of stress hormones such as cortisol, affecting blood sugar metabolism, blood pressure, immunity, and cardiovascular health.
According to Dr. Tien, the elderly, people with cardiovascular disease, hypertension or existing sleep disorders are often more sensitive to the effects of hot weather. For quality sleep, you should keep the bedroom temperature around 24-26 degrees Celsius, use blankets and sleepwear made of breathable materials, and avoid intense exercise or eating too much before going to bed.
Besides, you should keep the bedroom airy and maintain a regular bedtime. Some natural nutrients such as anthocyanin-rich blueberry and pterostilbene combined with ginkgo biloba (ginkgo) can support brain circulation, protect nerve cells, and contribute to improving sleep quality.
