Keeping windows shut/curtains drawn builds up heat?

[PlinkPlonkFizz]

In preparation for the heatwave spike, I've been thinking about the advice to keep windows shut and blinds and curtains drawn.

AIBU to think this just creates a heat spot between your window and curtain and you'd be better off to open the top sash to allow that heat to escape?

I agree. Keeping the windows closed isn’t the best approach if you’re in a home where you can set up a cross breeze. It’s makes things a bit cooler, but not as cool as they could be.

Even the berbers in the Sahara lift the floor flaps and the front flaps to ventilate their tents in 50C+ as a open sunshade is coolest. It’s not the best idea to completely seal yourself off with zero ventilation in extreme heat. It doesn’t keep you as cool as possible.

Closing windows is an ok approach in moderate heat and in an area where it does cool down quite a bit at night. I think this is only the advice because it’s the simplest advice to give. Explaining cross breezes and how to move them with fans and opening/closing curtains as the sun moves is probably too complicated for the government to communicate to the entire population. And the heat isn’t that “extreme” compared to hot countries so they get away with giving the simplest advice to make things a bit cooler. So that’s why I think they’re saying close all your windows and curtains in the morning and open them in the evening. Easy to remember and do and with widest application.

A breeze may make you feel / think colder but if it's hot and sunny you would be better keeping the room cooler and using water ( damp towel , spray) and a fan inside

Nah not in high humidity like we have here. All you’re doing with a fan is moving air around in an enclosed space and increasing the humidity by putting more water into that air- which is going to increase the heat index, not decrease it.

I lived in Cyprus for a while, our apartment had shutters. It took me several weeks to finally realise why when I looked at the neighbouring buildings they all had shutters down during the day.

My 'office' is in the loft room and I keep the velux and windows shut, makes a huge difference.