Heat and dehydration
High heat and humidity can cause headache, dizziness, cramps and worsening exhaustion. Reduce exertion, seek shade, replace fluids and electrolytes appropriately, and acclimatise gradually. Confusion, collapse, very high temperature or inability to drink requires urgent medical attention.
Food and stomach illness
Hand hygiene, safe water and freshly cooked food reduce risk but cannot eliminate it. Oral rehydration is often more important than immediately suppressing symptoms. Seek care for blood, severe pain, persistent vomiting, dehydration, high fever or illness in a vulnerable person.
Mosquito-borne disease
Dengue and other mosquito-borne infections occur in Thailand, including urban areas. Use repellent, clothing and screened or air-conditioned rooms. Fever with severe headache, rash, bleeding, marked weakness or worsening after an apparent improvement needs clinical assessment; avoid self-selecting medicines that may increase bleeding risk.
Respiratory and environmental problems
Respiratory infections spread in transport and crowded indoor settings, while seasonal smoke and pollution can aggravate asthma. Carry usual medication, monitor local air conditions and seek help for breathing difficulty, chest pain, blue lips, confusion or rapid deterioration.
Verify before you act
Rules, timetables, prices and local conditions can change. Use the official source links below for the latest position.