Studying for exams on a hot day: Don't overload your brain.

Besides the heat from the environment, the intense mental activity during exam season also causes the body to generate more internal heat, putting great pressure on the cardiovascular and nervous systems. If prolonged, students may experience memory loss, emotional decline, and an increased risk of heat exhaustion.

Exam preparation time at Le Van Thinh High School, Bac Ninh .

During exam preparation, the brain consumes a lot of oxygen and glucose. The more intense the mental activity, the more endogenous heat is generated. This means that students have to endure both external heat and heat from their own brain activity. This increases the burden on the cardiovascular and central nervous systems.

Experts point out the "golden hours" to help students learn quickly and remember for a long time during the hot season.

Children and adolescents regulate their body temperature less efficiently than adults. Therefore, they are more susceptible to heat exhaustion and heatstroke than adults under the same environmental conditions.

Hot weather is not only harmful physically. High ambient temperatures, poor sleep, and prolonged dehydration increase levels of stress hormones (such as cortisol). Students are more prone to irritability, discomfort, decreased motivation, anxiety, and emotional outbursts.

According to Dr. Nguyen Huy Hoang of the Vietnam Society of Underwater and Hyperbaric Oxygen Therapy, several psychological studies show that prolonged hot weather can increase the rate of sleep disorders, mild depression, and anxiety in children and adolescents. This explains why, with the same amount of homework, children often complain during hot weather, "I can't remember anything," or "The more I study, the more frustrated I feel."

To protect health and academic performance during the hot season, Dr. Hoang says the first thing to do is not to "try to endure it," but to reorganize your schedule based on your body's circadian rhythm and daily temperature chart. The core idea: dedicate the coolest hours to difficult subjects, and reserve the hottest hours for rest and recovery.

In addition, how you allocate your time during each session is also very important. Studying continuously for 2-3 hours without a break overloads the brain, causes body temperature to rise without proper dissipation, and significantly reduces memory quality. A principle supported by many experts is: study intensively for 40-45 minutes, then take a 10-15 minute break. During the break, students should stand up, rotate their wrists and ankles, stretch, walk around the room, and take a few deep breaths to "change the environment" for the brain and reduce stress.

Sleep is the most important "refreshing therapy" for the brain during exam preparation. During deep sleep, the brain reprocesses the day's information, transferring some short-term memories to long-term ones, and eliminates metabolites that cause nervous fatigue. Lack of sleep increases sensitivity to heat, raising the risk of dizziness, restlessness, difficulty concentrating, and irritability.

Therefore, students should aim for about 7-8 hours of sleep each night. Ideally, they should go to bed around 10-10:30 PM and wake up around 5 AM to take advantage of the cool morning air. Students should avoid staying up past 11 PM, as cutting short deep sleep will leave them feeling sluggish the next day, and even coffee or energy drinks are only temporary solutions and can harm cardiovascular health. A short nap of 20-30 minutes (no more than 45 minutes) in a cool room is a legitimate "doping" for the brain, helping them feel more alert in the afternoon.

"Shield" to protect students during the hot season.

In hot weather, the need for water increases significantly, but drinking too much plain water isn't good either. When you drink a lot of water without replenishing minerals, the sodium concentration in your blood can be diluted, leading to mild hyponatremia: headache, fatigue, nausea, cramps, and difficulty concentrating.

Therefore, Dr. Hoang noted that parents can guide their children to estimate the baseline water intake based on weight (for example, about 30 ml/kg/day depending on age and health condition), then add 0.5–1 liter of water if the weather is very hot or there is a lot of physical activity. Water should be divided into smaller portions and drunk throughout the day, avoiding waiting until the throat is parched before drinking.

Besides plain water, you can alternate between: diluted lemon water with a little salt or honey, which helps to lightly replenish electrolytes and provides vitamin C; coconut water in moderation, a natural source of potassium and sodium; and some herbal teas such as centella asiatica, houttuynia cordata, and light green tea, which have a cooling and mild diuretic effect, but pay attention to the hygiene of the water source and avoid drinking too much or too concentrated tea throughout the day.

Note that you should limit your intake of sugary drinks, energy drinks, milk tea, etc., because their high sugar content can cause significant blood sugar fluctuations, easily leading to feelings of "ups and downs" in energy, affecting mental stability and sleep.

In terms of nutrition, families should prioritize adding foods that are "cooling" and good for the brain. The brain needs certain "ingredients" to function optimally. Some important nutrient groups include: omega-3 fatty acids; choline; antioxidants; B vitamins...

In Vietnamese family meals, it's advisable to prioritize dishes that are "cool, light, and nutritious," such as crab and spinach soup, gourd soup with shrimp, fish soup with green vegetables, tofu, boiled vegetables, and fresh fruit after the meal. These dishes provide hydration, are rich in vitamins and minerals, and don't cause bloating like fried foods.

In the evening, light porridges such as lotus seed porridge, mung bean porridge, or longan and lotus seed porridge (if you are not allergic) can help calm the nerves and promote deeper sleep. Conversely, you should limit overly spicy, greasy, and fast food as they increase the burden on the digestive system and generate more heat in the body.

Not every family has air conditioning, but there are still many ways to relatively "reduce the heat" if you understand a little about thermal principles. During the day, close windows facing the harsh sun, draw light-colored curtains or thick blackout curtains to block heat radiation; if you open windows to let in the breeze, choose a direction with less direct sunlight. Use a fan combined with a bowl of ice water or a wet towel hung in front of the fan to create a cool breeze based on the evaporation mechanism. Air passing over the cold water surface will be "cooler," providing a noticeably more comfortable feeling.

In the evening, when the outside temperature drops, you can open the windows and position the fan to face outwards to "push" the hot air out of the room, creating a pressure difference that allows cool air from outside to flow in. Turn off unnecessary electrical appliances (incandescent lights, computers not in use, etc.) because these devices generate heat and significantly increase the room temperature.

"Alongside the physical environment, don't forget the 'emotional environment.' The hot weather combined with exam pressure can easily increase family stress. Parents should observe signs such as their children becoming noticeably less talkative, easily irritable, eating unusually little or too much, having difficulty sleeping, complaining of fatigue, or getting grumpy over minor things. These could be signs of both thermal and psychological overload. Adjusting the study schedule with your child, giving them time to rest, encouraging them, and sharing realistic expectations will significantly reduce the invisible pressure weighing on them," Dr. Hoang advised.

THIEN LAM-THUY DUNG

Source: https://nhandan.vn/on-thi-ngay-nong-dung-de-nao-bo-qua-tai-post964460.html