Heat Stress
Heat stress is the pressure heat puts on the body from outside — from air temperature, humidity, sun and wind. When it climbs beyond safe levels the body must work harder to stay cool, which is when heat illness and death become risks.
Scientific detail
Heat stress quantifies environmental thermal load on a human, incorporating dry-bulb temperature, humidity, radiation and wind. It is the input to physiological response models that predict heat strain. Standardised indices such as WBGT and UTCI translate multivariate weather into a single-value heat-stress metric used in occupational health, sport and public warning systems.
Related terms
Heat Strain
The body's internal, physiological response to heat stress.
Wet Bulb Globe Temperature
A composite heat index widely used to set safe limits for outdoor work, sport and military training.
Universal Thermal Climate Index
A modern, physiology-based heat index that estimates how the human body actually responds to weather.
Thermal Comfort
The condition in which a person is neither too hot nor too cold.
Mean Radiant Temperature
The average temperature of every surface radiating heat toward a person.
Where this concept shows up on MEER
Related projects
- Freetown, Sierra Leone
Reflective rooftops across informal settlements.
- Tanzania
Community-scale reflective interventions.
Related publications
Related stories
- Human stories
First-person accounts of life inside extreme heat.
- News & stories
Related resources
In HeatLens
- HeatLens
Interactive heat-risk assessment tool.
Explore in topic hubs
Curated collections of MEER research, projects, publications and stories that feature this term.
Heat Resilience
MEER's work on heat resilience: physiological modeling with JOS-3, WBGT and UTCI measurement, HeatLens risk assessment, and community projects that protect the most exposed populations.
Urban Heat
The urban heat-island effect, its measurement, and how MEER's reflective roofs, canopies and pavements reduce peak city temperatures and protect vulnerable urban populations.
Agriculture & Cooling
How reflective materials, canopies and passive cooling protect agricultural yields, livestock and rural livelihoods under extreme heat.
Communities & Stories
Human stories, community reporting and field partnerships that ground MEER's science in the lives of the people most exposed to extreme heat.