Action first
How to block heat from windows
Short answer
Stop sunlight before it reaches the glass where possible; otherwise close pale blinds or lined curtains before direct sun arrives.
What to do
- ✓Use an external shutter, awning or shade where practical.
- ✓Close internal coverings early.
- ✓Prioritise east, west and south-facing glazing.
- ✓Avoid blocking required ventilation or escape routes.
Why it works
This advice follows UK Health Security Agency guidance and the underlying principles of solar gain and shading.
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