Action first
How to cool a room without air conditioning
Short answer
Shade sunny windows early. Keep them closed while it is hotter outside than inside, then open safe windows when outside becomes cooler. Turn off avoidable heat sources and use a fan to cool people or help move cooler air.
What to do now
- ✓Close curtains, blinds or shutters on windows receiving direct sun.
- ✓If outside is hotter than your room, keep windows closed for now.
- ✓Turn off unused lights, computers, ovens and other equipment producing heat.
- ✓Use a fan across people for relief; it does not refrigerate a closed room.
- ✓Move to the coolest room available if one room remains much hotter.
When outside cools
- ✓Open windows only where it is safe to do so.
- ✓Open windows on different sides to create a path through the home.
- ✓If there is only one opening, place a fan near it facing outward to help expel warm air.
Why it works
Shading reduces solar heat entering through glass. Timed ventilation replaces warm indoor air only when outdoor air is cooler. Fans mainly improve personal comfort through moving air and evaporation.
Important exceptions
Safety comes first
Do not leave windows open where they create a fall, security or fire-safety risk. If anyone shows signs of heat illness, cool the person and follow health guidance rather than concentrating only on the room.
Related guides
Sources & evidence
Reviewed 2026-08-21
- UK Health Security Agency: Beat the heat: keep cool at home checklist ↗
Supports: Window timing, shading, ventilation, reducing internal heat and identifying higher-risk homes.
official guidance · Accessed 2026-08-21