Disclaimer

Data accuracy

Weather data is sourced from Open-Meteo, a free and open-source weather API. Temperature and humidity readings are based on the nearest available weather station and may not precisely reflect conditions at your exact location.

The Heat Safety Index is calculated using the Stull (2011) wet bulb temperature formula, a peer-reviewed scientific method. Threshold values are based on published physiological research (Vecellio et al., 2022).

Not medical advice

The Heat Safety Index and all related information on HeatSafe are for general awareness only. They do not account for individual health conditions, age, medications, fitness levels, or acclimatisation.

If you or someone around you is experiencing symptoms of heat illness — dizziness, confusion, nausea, rapid heartbeat, or loss of consciousness — seek immediate medical attention. Do not rely on HeatSafe to make medical decisions.

In a medical emergency in India, call 108 (Medical/Ambulance) or 112 (All emergencies).

Limitations

• HeatSafe assumes outdoor conditions in shade, at rest, for a healthy young adult with adequate hydration. The safety limit could be even lower in direct sun, during activity, or for the elderly, infants, pregnant women, and people with chronic illness.
• Direct sunlight significantly increases heat stress beyond what wet bulb temperature captures
• Indoor conditions, air conditioning, and physical activity are not accounted for
• Data updates approximately every hour — conditions may change rapidly

No liability

HeatSafe and its creators accept no liability for decisions made based on information displayed on this website. Use this tool as one of several inputs when making decisions about outdoor activity in hot weather.

Contact

hello@heatsafe.in