Action first
Cooling a room without cross-ventilation
Short answer
Prevent heat entering first, then use a fan at the available opening when outside is cooler and draw replacement air from the coolest safe adjacent space.
What to do
- ✓Shade the window.
- ✓Open the internal door if appropriate.
- ✓Expel warm air with a fan after outside cools.
- ✓Use personal cooling while the room temperature falls.
Why it works
This advice follows UK Health Security Agency guidance and the underlying principles of single-sided ventilation and personal cooling.
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