Extreme heat in Indonesia: signs of heat stroke, first aid and staying safe

What to have ready

• A water bottle so you can drink a little throughout the day without waiting until you are thirsty.
• A hat or umbrella, and loose, light, light-coloured clothing.
• Sunscreen of at least SPF 30 for skin not covered by clothing.
• The Info BMKG app or access to cuaca.bmkg.go.id to follow the weather forecast.
• A cloth or towel and a water spray to cool the body.
• The 119 number and the address of the nearest puskesmas or hospital A&E.

How to stay safe in hot weather

1. Follow BMKG forecasts and advice

   Check the forecast for your location in the Info BMKG app or at cuaca.bmkg.go.id, and BMKG’s weekly outlook. In its outlook for 13–19 October 2026, BMKG asked people to keep preparing for the effects of hot weather and drier air.

2. Plan when you are outdoors

   The Ministry of Health (Kemenkes) advises staying in the shade as much as possible between 11:00 and 15:00. If you must do heavy work or exercise, WHO suggests choosing the coolest time of day, such as the early morning, and resting in the shade.

3. Drink before you are thirsty and protect your skin

   Drink water regularly without waiting for thirst. Kemenkes advises avoiding caffeinated drinks, energy drinks, alcohol and sugary drinks in hot weather, and wearing a hat or using an umbrella, loose light-coloured clothing and sunscreen of at least SPF 30.

4. Look after the people most at risk

   Check on relatives or neighbours who are older, live alone or have heart, lung or kidney disease, and make sure children drink enough. Never leave anyone in a parked vehicle, whether the windows are open or closed.

5. Deal with heat exhaustion early

   If someone has a headache, heavy sweating, pale clammy skin, fast breathing, nausea or aching muscles, move somewhere cool straight away, drink water, replace lost electrolytes (the body’s mineral salts), spray the body with water and rest for at least 30 minutes. If symptoms continue, get checked at a health facility.

6. Call 119 if you suspect heat stroke

   If someone who is overheated becomes confused, talks nonsense, has a seizure, collapses or has hot, dry skin, call 119 or take them to A&E. While you wait, move them into the shade, loosen their clothing and cool them with wet cloths, a fan or cold compresses on the neck, armpits and groin.

Cost of weather information and emergency help

Free. BMKG weather information on its website and the Info BMKG app costs nothing, and calls to the 119 medical emergency service are free under Communications Minister Regulation 14/2018. Check-ups and treatment at health facilities follow your JKN (BPJS Kesehatan) membership status.

At work, Minister of Manpower Regulation 5/2018 requires employers and/or managers to meet occupational safety and health (K3) standards for the working environment, including measuring and controlling the working climate where there is a heat source or poor ventilation. We found no Ministry of Manpower rule that sets a weather temperature limit for outdoor work.

Heat exhaustion and heat stroke: two different stages

Kemenkes describes heat exhaustion as the stage before heat stroke. The signs are a headache, heavy sweating, pale, clammy and cool skin, fast breathing, nausea and aching muscles. It can be managed by drinking enough water, replacing lost electrolytes, spraying the body with water and resting for at least 30 minutes.

Heat stroke is the most serious effect of hot weather, when the body can no longer control its temperature. According to Kemenkes, body temperature can rise quickly to 41°C within 10–15 minutes and the body stops sweating. Another Kemenkes article lists signs such as a body temperature above 40°C, confusion, agitation, headache, nausea and vomiting, a pounding heart, muscle weakness, seizures and fainting.

WHO calls heat stroke a medical emergency with a high death rate. The first step is to call the emergency services, then cool the person by any means available while waiting for help. WHO also says aspirin or paracetamol should not be given to someone with heat stroke, and that an unconscious person should be placed on their side.

• Kemenkes: recognising the signs of heat stroke (Indonesian) ↗
• Kemenkes (Keslan): preventing heat stroke (Indonesian) ↗
• WHO: what to do if you see signs of heat stroke ↗

Who is most at risk

According to WHO, the highest risk is among people over 65, people with heart, lung or kidney disease, disabled people, people who live alone, and babies and children. Kemenkes also names children and people who are already ill as vulnerable when temperatures rise.

Outdoor and manual workers, athletes and field staff are exposed to heat through their work. A Kemenkes article distinguishes heat stroke caused by long periods of heavy physical activity in a hot environment from classic heat stroke, which more often affects older people, people with chronic illness, alcohol users and very young children.

So check on vulnerable relatives and neighbours on hot days. WHO advises staying in the shade, spending 2–3 hours a day somewhere cool, and keeping windows and blinds closed during the day and opening them at night.

• WHO: Heatwaves, how to stay cool ↗
• WHO: Climate change, heat and health ↗

Outdoor workers and hot workplaces

Minister of Manpower Regulation (Permenaker) 5/2018 on occupational safety and health (K3) in the working environment requires employers and/or managers to meet K3 standards, including keeping physical factors such as the working climate below the threshold limit value (NAB). Heat stress at work is assessed with the wet bulb globe temperature index (ISBB), calculated from dry air temperature, natural wet bulb temperature and globe temperature.

Article 9 requires the working climate to be measured and controlled in workplaces with a heat source and/or poor ventilation. If the results exceed the threshold, controls can include removing, replacing or isolating the heat source, providing ventilation, providing drinking water, setting or limiting exposure time, and suitable work clothing and personal protective equipment.

For people working in the sun, we found no Ministry of Manpower (Kemnaker) rule that sets a weather temperature limit, so the general advice from BMKG, Kemenkes and WHO applies: drink enough, wear protection and sunscreen, rest in the shade and move heavy work to cooler times. Breaches of K3 standards can be reported to labour inspectors through Lapor Menaker (lapormenaker.kemnaker.go.id); Kemnaker says the reporter’s identity is kept confidential.

• Permenaker 5/2018 on K3 in the working environment (Indonesian) ↗
• Kemnaker: the Lapor Menaker channel for labour and K3 standards (Indonesian) ↗

Temperature and hot-weather information from BMKG

BMKG, the meteorology agency, publishes forecasts for your location at cuaca.bmkg.go.id and in the Info BMKG app, and a weekly outlook that includes advice during hot weather. It also posts updates on social media as @InfoBMKG, and the BMKG contact centre is on 196.

According to BMKG, hot weather around October is mainly caused by the sun’s apparent position south of the equator and dry easterly winds (the Australian monsoon) with little cloud. In 2021 BMKG explained that a heatwave means hot air lasting 5 or more days in a row with daily maximum temperatures 5°C or more above average, and said this does not happen in Indonesia.

On 22 September 2026 BMKG said a very strong El Niño was under way and that the start of the 2026/2027 rainy season was expected to be late in 61.08% of seasonal zones; in many areas rain is not expected until November or December 2026. In its outlook for 13–19 October 2026, BMKG advised using sunscreen and drinking enough, especially for people active outdoors during the day.

• BMKG: very strong El Niño and the 2026/2027 rainy season (Indonesian) ↗
• BMKG: Indonesia weekly outlook, 13–19 October 2026 (Indonesian) ↗
• BMKG: explanation of heatwaves (Indonesian) ↗

Things to check carefully

Frequently asked questions