Why it works
Thermal mass explained
Short answer
Thermal mass is a material’s ability to absorb and store heat. It can smooth temperature swings but also keep a home warm at night.
The simple explanation
- ✓Concrete, brick and stone store substantial heat.
- ✓Shading prevents that mass charging with unwanted summer heat.
- ✓Cool night air can discharge stored heat.
Why it works
This advice follows UK Health Security Agency guidance and the underlying principles of thermal mass and heat capacity.
Important exceptions
Safety, health, weather and the design of your home can change what is appropriate. Stop if an action makes conditions worse.
Related guides
Sources & evidence
Reviewed 2026-08-21
- UK Health Security Agency: Beat the heat: keep cool at home checklist ↗
Supports: Shading, ventilation, reducing indoor heat and protecting people at higher risk.
official guidance · Accessed 2026-08-21