When the monsoon rain stops, the scorching heat follows. Tropical nights are a major factor that disrupts sleep during the summer. It refers to the phenomenon where the temperature does not drop below 25 degrees Celsius from 6 PM to 9 AM the next day. If you cannot sleep properly, your condition the next day worsens, your immunity drops, and it is not good for your health.
Professor Shin Won-chul of the Sleep Center at Gangdong Kyunghee University Hospital Neurology Department said, "Body temperature drops until about two hours before waking up, then gradually rises, leading to awakening," and "If the temperature exceeds 25 degrees Celsius during sleep, the body temperature does not decrease properly, and melatonin secretion is hindered, making it difficult to enter deep sleep."
People maintain their highest body temperature about two hours before sleeping. When they fall asleep, their body temperature gradually begins to drop, and the sleep hormone melatonin is secreted. This leads to a deep sleep. However, if this balance is disrupted, they cannot sleep deeply and wake up frequently.
To prevent sleep disturbances that occur whenever tropical nights happen, it is important to keep the bedroom cool and refreshing. During the day, use blinds and curtains to block hot sunlight and air from entering the house. At night, try to minimize the use of electronic devices that generate a lot of heat. High-performance computers and large TVs also produce significant heat. Therefore, it is advisable not to use them 1 to 2 hours before going to bed.
Using well-ventilated, cool bedding is also a good way to achieve restful sleep. Utilizing breathable bedding made of cotton, Tencel, or bamboo rayon materials allows body moisture to be easily absorbed. This helps moisture evaporate quickly from the skin, lowering body temperature. It is also beneficial to use cooling mattresses and pads.
Using a smartphone or similar devices in bed before sleeping makes it difficult to fall asleep easily due to blue light. Blue light reduces the production and secretion of melatonin. This prevents deep sleep and interferes with restful sleep.
Professor Shin Won-cheol said, "Even if you try to reduce blue light exposure through blue light blocking films or by setting your smartphone to night mode, you cannot completely block the emission," and advised, "You should not use smartphones, tablets, or similar devices starting one hour before sleep."
It is also important to drink enough fluids. Consuming sufficient hydration throughout the day can keep the body cool. It is also beneficial in preventing heat-related illnesses during the daytime. On summer nights, drinking cold ice water before sleeping can temporarily lower body temperature quickly and help achieve restful sleep.
It is known that a lukewarm water shower is good for a good night's sleep. However, Professor Shin Won-cheol said, "During tropical nights, cold water showers are also beneficial." Cold water showers cause blood vessels to constrict and activate the sympathetic nervous system, which excites the body and can interfere with deep sleep. However, during tropical nights, the hot temperatures persist, so it is better to quickly lower body temperature.
It is also recommended to maintain a humidity level that is good for sleep. If using a dehumidifier, it should be adjusted to around 50%, which is the optimal humidity for sleep.
Air conditioning can help with restful sleep, but setting the temperature too low is not advisable. It can cause cooling sickness, and if body temperature drops too much, blood vessels constrict. Blocking the release of high deep body temperature can hinder the overall reduction of body temperature. It is recommended to set the room temperature to an appropriate level (23-26°C) considering the environment.
If sleep decreases with age, it is good to correct usual habits to improve sleep quality. Professor Shin Won-cheol said, "After age 60, the hypothalamus in the brain with the biological clock ages, making it harder to sleep than before," and added, "You need to manage your surroundings to compensate for the brain's declining function."
Create a bedroom environment where noise and temperature are controlled to facilitate sleep, and engage in light exercise in the afternoon. Reduce intake of substances like caffeine that disturb sleep to promote a body condition conducive to melatonin production.
If you cannot fall asleep within 20 minutes, it is better to sit in the living room and read a book or listen to relaxing music rather than keep lying down. Doing some stretching while practicing diaphragmatic breathing is also beneficial. After adjusting the stimulation like this and feeling sleepy, it is better to lie down again.
