Bathing in warm water incorrectly during the cold season can cause a stroke

Cold air is covering the North and spreading to the Central region, while the South is in the dry season with decreasing temperatures at night and early morning. Dr. Nguyen Tan Sang, Department of Neurology, Center for Neuroscience, Tam Anh General Hospital, Ho Chi Minh City, noted that many people like to bathe in warm water to keep the body warm when the ambient temperature is low. However, it is recommended that improper warm water bathing can cause heat shock to the vascular system, potentially causing a risk of stroke. This risk occurs higher in people who are older or have underlying diseases such as hypertension, cardiovascular disease, or atherosclerosis.

When the weather is cold, the body reacts by constricting blood vessels to retain heat. Bathing with water above 38 degrees Celsius after being outdoors or just exposed to cold air, blood vessels tend to dilate quickly within a few seconds. “The transition from vasoconstriction to vasodilation too quickly is like tightening and then opening a water pipe,” Dr. Sang explained, adding that at this time, the vessel wall is under great pressure, easily tearing, causing brain hemorrhage or forming a thrombus causing a blockage.

The habit of pouring warm water directly on the head can cause the brain and blood vessels in the head and neck area to be suddenly affected by heat. Heat effects not only change blood pressure but also affect heart rate and the autonomic nervous system. When the vessels dilate rapidly, the heart is forced to increase its rate to pump blood to compensate.

You should not shower as soon as you come into the house from a cold environment or from a cold room to a hot place. In the cold season, blood vessels constrict and blood pressure easily increases, especially early in the morning and late at night. “If your body is cold and shivering, if you take a hot bath immediately, the risk of a “double” stroke increases because the heart and brain have to endure two consecutive heat shocks,” said Dr. Sang.

The Neuroscience Center, Tam Anh General Hospital, Ho Chi Minh City, recently recorded a number of stroke cases occurring right after taking a hot bath in the cold season. Like Mr. Long, 67 years old, has high blood pressure and has a habit of taking hot baths in the evening. The day he was admitted to the hospital, he suddenly collapsed in the bathroom, his mouth twisted, and his right side was paralyzed. Results of MRI and CT angiography showed cerebral hemorrhage in the basal ganglia area – a vulnerable location in people with persistent hypertension. Dr. Sang explained that blood vessels in older people are hardened and less elastic, and sudden changes in temperature can easily cause blood vessels to be affected and rupture.

Similarly, Ms. Hoa, 58 years old, had a cerebral infarction due to a rapid drop in blood pressure that reduced blood flow to the brain. Family members said she closed the room, blocked the ventilation because she was afraid of the cold, and after about 10 minutes of bathing, she felt dizzy and fainted. Dr. Tan Sang assessed that this is a silent type of stroke, easily occurring in closed spaces and often mistaken for fainting due to fatigue.

Doctor Tan Sang advises that in the cold season, when bathing, you need to let your body adapt slowly, starting with warm water of 35-37 degrees Celsius, pouring on your hands, feet, and shoulders first, then washing your head, avoiding pouring hot water directly on your head. Do not bathe for a long time in a closed bathroom, avoid bathing immediately after going out in cold weather, exercising vigorously or after eating a full meal. After bathing, you should dry quickly, dress warmly, and do not step into a suddenly cold environment to limit blood pressure fluctuations. Signs such as dizziness, headache, numbness in limbs, blurred vision, and difficulty speaking after bathing are often overlooked because they are thought to be due to changes in temperature. Meanwhile, these signs can be the starting point of an acute stroke.

People with cardiovascular disease, hypertension, diabetes, dyslipidemia, stroke or over 60 years old need to be especially careful. They should control their blood pressure regularly and have regular check-ups at neurology and cardiology specialists. Cerebrovascular abnormalities can be detected through CT and MRI scans with new generations of machines such as MRI 3 Tesla, CT 1975 or CT 100,000 slices, thereby assessing the degree of stenosis, aneurysm, sclerosis or the risk of thrombosis. Early detection helps doctors develop appropriate control and treatment regimens for patients, reducing the risk of sudden temperature changes during the cold season.