Wet-Bulb Temperature

Harvard Study Reassesses Human Survival Threshold

A recent study by Harvard researchers challenges the long-standing belief that the human survivability limit for wet-bulb temperature is 35°C, proposing a lower threshold of around 31°C for safe human endurance.

What is Wet-Bulb Temperature?

1. Wet-bulb temperature refers to the lowest temperature that air can reach through evaporation of water at constant pressure.
2. It is measured by wrapping a wet cloth around the bulb of a thermometer and allowing the water to evaporate.
3. The cooling effect from evaporation lowers the thermometer reading, providing the wet-bulb temperature value.
4. This metric reflects both heat and humidity, making it more realistic for assessing human heat stress than air temperature alone.
5. A high wet-bulb temperature means evaporation (and thus sweating) becomes less effective, reducing the body's ability to cool itself.
6. It is a critical factor in areas like climate science, agriculture, health, and disaster preparedness.
7. Conditions above the survivability threshold—even for short periods—can lead to fatal heat stress, particularly in vulnerable populations.

 

Also Read
UPSC Foundation Course	UPSC Daily Current Affairs
UPSC Monthly Magazine	CSAT Foundation Course
Free MCQs for UPSC Prelims	UPSC Test Series
ENSURE IAS NOTES	Our Booklist