Heat safety
Humidity and heat risk
Short answer
Humidity reduces sweat evaporation, so the same air temperature can place more strain on the body when moisture is high.
What to do
- ✓Use air conditioning or a cooler, less humid space if available.
- ✓Do not rely on an evaporative cooler in humid air.
- ✓Watch for symptoms and reduce exertion.
Why it works
This advice follows NHS guidance and the underlying principles of humidity and heat risk.
Important exceptions
This page cannot diagnose anyone. Follow the linked health guidance and seek urgent help for emergency symptoms.
Sources & evidence
Reviewed 2026-08-21
- NHS: Heat exhaustion and heatstroke ↗
Supports: Heat-illness symptoms, cooling actions and when to seek emergency help.
health guidance · Accessed 2026-08-21