Overview
- Specialists and official bodies including the Energy Saving Trust and UKHSA advise keeping windows, doors, blinds and curtains closed during the hottest hours to block solar heat and limit indoor warming.
- Opening windows between about 11am and 6pm, when outside air is often hotter than inside air, will usually draw heat into a home rather than cool it, experts warn.
- Ventilate only when outdoor air is cooler than indoors, typically late evening, overnight or early morning, and open opposite windows to create a cross-breeze that flushes stored heat.
- Use layered window treatments — thermal or blackout curtains over blinds or shutters, light-coloured reflective fabrics and sheer layers — to reduce solar gain without costly equipment.
- Fans and simple tricks such as placing a bowl of ice in front of a fan work best once temperatures fall, and following these low-cost steps can ease discomfort and reduce health risks in heat-prone UK homes; a limited reporter test from Yorkshire Live supported the sealed-during-day approach.