Having grown up in the deep south (St. Thomas, Ontario) where the summers were hot and humid, the recent spell of days and evenings of ongoing sun and heat in my now moderate environment (Victoria, BC) reminded me of one way of keeping the house cool: keep the open windows shaded from the sun when it is directly shining on that side of the house; unshade the open windows when the sun is not.
And it is all in the angle of the blind.
Downward slanted……….
……….or up.
The breeze can flow through but the hot rays are halted.
We did not have these nifty wooden narrow blinds. The ones I recall were called venetian blinds and you had to be careful not to bend them too much while peering between them or they would crack.