Experts reveal that on 8-9 April 2026, the heat index will be at an 'extreme danger' level, warning that being outdoors in the afternoon under hot, still air may cause fainting or even death.
On 5 March 2026, environmental and health expert Sonthi Kotchawat, from the Environmental Scholars Association, posted on his personal Facebook.Sonthi KotchawatHe stated a warning: on 8 and 9 April 2026, being outdoors in the afternoon under hot, still conditions may cause fainting and death.
Currently, Bangkok and its vicinity have outdoor air temperatures reaching up to 39 degrees Celsius, with relative humidity in some areas exceeding 60%, resulting in a heat index (HI) around 58.7 degrees Celsius. This falls under the 'Extreme Danger' category. Because this exceeds 52 degrees Celsius, it carries a very high risk of heat stroke or sunstroke.
Core body temperature can rise to 40 degrees Celsius within just 10-15 minutes. If exposed outdoors for 45 minutes, the body's temperature regulation begins to fail, skin becomes red and dry (no sweating), risking loss of consciousness. Exposure to sunlight for 1 hour may lead to critical neurological conditions and death.
1. The cause of the extreme heat and heat index above 50 degrees Celsius on 8-9 April 2026 in Thailand results from several main factors combined:
1.1. The El Niño phenomenon and global warming: a strong El Niño causes Southeast Asia to be hotter and drier than usual, combined with global warming raising average temperatures.
1.2. High relative humidity: even if the actual temperature is below 50 degrees Celsius, high humidity from southerly winds bringing moisture from the sea reduces sweat evaporation, causing the body to retain more heat, pushing the heat index above 50-60 degrees Celsius.
1.3. Early April is when the sun is directly overhead in parts of Thailand, maximizing heat intensity.
2. Protective measures
2.1. Avoid outdoor activities during daytime, especially between 1:00-4:00 p.m.
2.3. Drink sufficient water—at least 6-8 glasses per day—and avoid alcoholic beverages.
2.3. Wear breathable clothing: choose light-colored, lightweight fabrics to help dissipate body heat.
2.4. Stay in the shade, avoid direct sun, wear UV400 sunglasses. When indoors, take cool showers with powder application, and use air conditioning or fans to cool down.
Information sourced from Sonthi Kotchawat’s Facebook.