5 Dangerous Signs of Heat Stroke Leading to Stroke: Who Is at Highest Risk?

Exploring the connection between "heat stroke" and "stroke" (cerebrovascular disease), where extreme heat causes thickened blood and overworks the heart, increasing the risk of paralysis. It also offers advice on self-care and identifies high-risk groups during the hot season.

The intense heat in Thailand is not just irritating; it can hide a silent, life-threatening danger called "heat stroke". Many may not realize that temperatures soaring above 40 degrees Celsius act as a critical trigger leading to "stroke" (cerebrovascular disease), which can cause sudden paralysis.

How do heat stroke and stroke differ?

Although their names sound similar, they have different mechanisms. "Heat stroke" occurs when the body cannot dissipate heat fast enough, raising body temperature above 40 degrees Celsius and causing internal organs to malfunction. "Stroke" happens when the brain lacks blood due to narrowed, blocked, or burst blood vessels. While they are not the same disease, severe heat is a key factor that can cause blood vessels in the brain to narrow, block, or rupture, especially in those already at risk.

Check these 5 warning signs of "heat stroke"

If you or someone close must be outdoors or in extreme heat, watch for these abnormal symptoms:

1. A high fever exceeding 40.5 degrees Celsius
2. Headache, dizziness, fatigue, weakness, and possible loss of consciousness
3. Neurological abnormalities such as seizures, confusion, unsteady walking, slow responses, and incoherent speech
4. Lack of sweating due to malfunctioning sweat glands, causing the skin to turn very red
5. Dark-colored urine from muscle breakdown, which may lead to kidney failure

4 dangerous mechanisms: Why does heat cause brain blood loss?

Extreme heat severely affects the blood and heart system as follows:

• Dehydration and thickened blood: Excessive sweating thickens the blood, increasing the risk of blood clots blocking vessels.
• Overworked heart: The body speeds up the heartbeat to release heat, which can cause irregular heartbeats and dislodged clots that block brain vessels.
• Low blood pressure: Blood vessels dilate to cool the body, reducing blood supply to the brain.
• Systemic inflammation: Heat stroke triggers abnormal blood clotting, raising the risk of blockages.

Who are the "high-risk groups" needing special caution?

Those who must be closely monitored in hot weather include the elderly, people with high blood pressure, diabetes, heart disease, outdoor workers, and those with a history of stroke.

How to protect yourself and cope with extreme heat

• Sip water often: Drink plain water throughout the day even without thirst to prevent dehydration.
• Avoid direct sunlight: Stay in the shade between 11:00 a.m. and 3:00 p.m. If you must go outside, wear a hat and use an umbrella. Importantly, never leave children, pets, or the elderly in a parked car under the sun.
• Wear breathable clothing: Chooselight-colored fabricsthat allow good ventilation and are not tight-fitting.
• Reduce heat buildup: Take cool showers or wipe pulse points such as the neck, armpits, and groin with a wet cloth.
• Watch for warning signs: If you experience dizziness, intense heat, drowsiness, nausea, or seizures, seek immediate medical attention.
• Manage your environment: Close curtains or blinds to block heat from entering your home and minimize use of ovens or stoves.

Preventing heat stroke is not just about cooling down; it is about reducing the risk of sudden cerebrovascular diseases. If you or someone close is in a high-risk group, paying attention to even minor warning signs may save lives and prevent disabilities.

Information provided by Dr. Pimolpan Wisessarakun, a specialist in neurology and internal medicine at World Medical Center (WMC).