Heat stroke is easily confused with heat stroke

Exposure to hot sunlight for a long time causes blood vessels to dilate, while exposure to cold environments causes blood vessels to constrict. The continuous contraction and expansion process puts vessel walls under great pressure, especially in the elderly or with underlying diseases, according to Dr. Nguyen Tan Sang, Department of Neurology, Center for Neuroscience, Tam Anh General Hospital, Ho Chi Minh City.

For example, people who work outside in the sun and then suddenly enter an air-conditioned room or vice versa cause their blood pressure to fluctuate sharply, increasing the risk of ruptured blood vessels in the brain. Explaining the mechanism that causes this condition, Dr. Sang said that when exposed to high temperatures, the body reacts by dilating blood vessels and increasing sweating to dissipate heat. Working or going out in the sun for a long time causes the body to become dehydrated, circulatory volume is reduced, blood is often thicker and circulates more slowly. This is a favorable condition for blood clots to form, causing cerebral embolism, leading to cerebral infarction.

In addition, exposure to heat forces the heart to work harder to maintain circulation and regulate body temperature. People with cardiovascular disease, hypertension, and atherosclerosis are susceptible to stroke when the temperature changes suddenly due to damaged blood vessels.

An analysis published in the American Library of Medicine (PubMed) in 2023, synthesizing 20 international studies, showed that too hot environmental temperatures increase the risk of hospitalization due to stroke by 10% and increase the risk of death by 9% compared to the reference temperature (about 35 degrees Celsius).

In the past month, Tam Anh hospital received more than 10 heat-related stroke cases. For example, Ms. Hong, 58 years old, with a history of hypertension, after riding a motorbike for more than an hour in the hot afternoon sun began to feel dizzy, had difficulty speaking, and had weakness in her right arm. A CT angiogram showed cerebral infarction due to embolism. The doctor revascularized her brain with fibrinolytic drugs combined with medical treatment. After treatment, her arm and leg muscle strength improved clearly.

As for Mr. Phuc, 61 years old, with a history of diabetes and hypertension, after repairing a water tank on the terrace in the sun, he started having headaches, dizziness, and nausea, thinking it was heatstroke. About two hours later, he was paralyzed on the left side of his body, was taken to the emergency room, and a CT scan determined acute cerebral infarction due to middle cerebral artery occlusion.

The hospital activated the Code Stroke emergency procedure, emergency cerebral revascularization, and combined resuscitation treatment. After three days of treatment, the patient is awake and continuing to practice physical therapy to improve movement.

According to Dr. Sang, signs of stroke such as headache, dizziness, lightheadedness, nausea, and numbness in the arms and legs after exposure to the sun are easily mistaken for heat stroke or exhaustion, causing patients to delay treatment during the “golden time”.

Heatstroke often causes fatigue, thirst, red hot skin, sweating or fever but the limbs still move normally. Meanwhile, stroke often has additional neurological signs such as mouth distortion, weakness or numbness on one side of the body, difficulty speaking, blurred vision or loss of balance. When in doubt, you can quickly check by asking the patient to smile, say a simple sentence and raise both hands at the same time.

Doctors recommend that people limit going outdoors between 10:00 a.m. and 4:00 p.m. on hot days. Drink enough water every day, wear sunscreen, wear a hat, and when going out, limit constantly going in and out of air-conditioned rooms to avoid temperature differences. Early screening for cerebrovascular diseases plays an important role in preventing stroke in at-risk groups.

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, reducing risks from harsh weather conditions.