Before prolonged outdoor activity in Singapore, check the Wet-Bulb Globe Temperature (WBGT) for the activity location. Under the public advisory, Moderate heat stress calls for reducing outdoor activity and taking regular breaks in shade or indoors. At High heat stress, minimise outdoor activity and take more frequent or longer breaks. Follow the school or venue’s instructions for its own activity. MSS heat stress map · Heat Stress Advisory
If someone becomes confused, has a seizure or becomes unresponsive during or after heat exposure, call 995 immediately. Tell the operator about the heat or exertion, move the person to a cooler place if safe, begin cooling and follow the operator’s directions. Red Cross heat stroke first aid · SCDF emergency medical services
- Check heat stress at the venue before the session and recheck if conditions change.
- Plan a cooler place for breaks and make it easy for students to stop and speak up.
- Treat confusion, seizures or unresponsiveness after heat exposure as an emergency.
On this page · Read WBGT Before Planning Outdoor Activity · Change the Session Before Anyone Feels Unwell · Respond When Someone Feels Unwell in the Heat · Frequently Asked Questions
Read WBGT Before Planning Outdoor Activity
WBGT combines air temperature, humidity, wind and solar radiation. It answers a different question from the temperature shown by a weather app. The MSS map publishes a recent 15-minute average at its measurement locations. Select the relevant area and look at the time of the update. Your actual venue can still feel hotter or cooler depending on shade, airflow and local conditions. MSS explanation of WBGT and measurement
What Low, Moderate and High mean
- Low, below 31°C WBGT. The general advisory allows usual activity. Keep water and shade available and watch for symptoms.
- Moderate, 31°C to below 33°C WBGT. Reduce outdoor activity and arrange regular breaks in shade or indoors.
- High, 33°C WBGT and above. Minimise outdoor activity and increase break frequency or length. Consider moving the session indoors or changing the time.
These bands are the public advisory for prolonged outdoor activity in direct sun. Schools and sports operators can set their own arrangements for particular groups or events. Use their instructions as well as the latest environmental information. Official heat stress categories · Sport Singapore safety guidance
Change the Session Before Anyone Feels Unwell
Start with the activity itself. Shorten repeated runs, reduce time standing in the sun and plan an indoor or shaded break area. Assign someone to watch conditions and someone to check on participants. A plan for a school sports day needs to account for spectators and waiting groups as well as the students who are competing.
Give students permission to stop
Use plain words such as “Tell the teacher if you feel dizzy, sick or unusually weak.” Make it clear which adult to approach when the coach is on the far side of the field. A student can alert staff if a teammate looks confused or is behaving unusually. Follow the teacher or venue’s directions about returning to an activity.
Make a separate plan for care needs
Children or older adults who have health conditions may need individual advice. Share relevant information with the school or organiser in advance through their designated channel. Ask the person’s care team what symptoms or conditions should change the plan. MOH advises extra caution for seniors and others more vulnerable to heat stress. MOH advice for seniors and caregivers
Respond When Someone Feels Unwell in the Heat
If someone feels dizzy, weak or sick during activity, stop and help them get to a cooler place if safe. Tell the supervising adult. Seek medical advice if symptoms are worrying or persist. A person who becomes confused, has a seizure or cannot be roused needs emergency help. Call 995 and start cooling while waiting. Do not give a drink to someone who is confused, unconscious or unable to swallow safely. Red Cross heat illness guidance · SCDF emergency medical services
Give responders the entrance and the symptoms
Say what the person was doing, when symptoms started and what you have done so far. A field, stadium or park can have several entrances. Give the gate or landmark that responders can reach and tell them if there are access barriers. Stay with the person where safe and follow the operator’s directions.
Frequently Asked Questions
Is 33°C on my weather app the same as 33°C WBGT?
No. WBGT also accounts for humidity, wind and sun exposure. Use the official heat stress map for the advisory category. MSS heat stress map
Can a session continue just because there is shade?
Shade can reduce exposure, but activity intensity, ventilation, duration and the people taking part still matter. Use the venue’s instructions and stop if someone feels unwell.
What if thunder starts on a hot day?
Take shelter and follow the venue’s lightning procedure. WBGT describes heat stress. Check MSS for lightning information separately. MSS lightning map
Continue With the Singapore Emergency Playbook
- MRT Breakdown in Singapore | What to Do on a Stalled Train or at an Affected Station
- Lightning in Singapore | What to Do If You Hear Thunder at School, the Pool or a Park
- Haze in Singapore | How to Use PSI and PM2.5 for School and Outdoor Plans
- School Emergency in Singapore
- Emergency Numbers in Singapore
Official guidance checked 8 November 2026.