Action first
How to cool a south-facing room
Short answer
Shade the glass before sunlight enters, keep hotter daytime air out and ventilate after outdoor temperatures fall.
What to do
- ✓Use external shade if possible.
- ✓Close internal coverings before the sun reaches the room.
- ✓Reduce indoor heat sources.
- ✓Night-purge the room when conditions allow.
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