Heat safety
Guide
What the score means and what to do
Reading the HTSI score
- Safe0 to 30
- Caution31 to 55
- Danger56 to 80
- Extreme Danger81 to 100
HTSI blends the heat index (40%), wet bulb globe temperature (35%) and UTCI (25%) from temperature, humidity, wind and sunshine, then adjusts for personal vulnerability. Alerts start above 55.
Everyday protection
- Drink water regularly even if you do not feel thirsty; avoid alcohol and excess caffeine.
- Wear lightweight, light-coloured, loose-fitting clothing.
- Never leave children, elderly people or pets in a parked vehicle.
- Check on elderly neighbours and relatives twice a day during heatwaves.
- Use ORS or homemade drinks (lemon water with a pinch of salt and sugar) to stay hydrated.
- Avoid strenuous outdoor activity between 12pm and 4pm.
Heat exhaustion
Heavy sweating, weakness, dizziness, nausea. Move to a cool place and hydrate immediately.
Heat stroke is an emergency
High body temperature, confusion, no sweating, rapid pulse. This is a medical emergency: call for help immediately.
If you or someone nearby shows confusion, a body temperature above 40 °C, hot and dry or clammy skin, a rapid pulse, or loses consciousness, this is heat stroke and a medical emergency. Call emergency services immediately, move the person to shade, remove excess clothing, and cool the body with water or ice packs on the neck, armpits and groin while waiting for help.