Well, the article lies. Every time there’s high air humidity there’s a distinct and worsening sour smell. My school did this to our bathroom windows (because it was more environmentally friendly than plastic options). Ugh.

Shutters? Those’ll do it.

It can slow things down, but once the light hits the curtain, the energy has gotten in, where it might dissipate slower, but it is still going to dissipate into the rest of the space.

Reflective curtains can do wonders, bouncing most of the light back out, mind. The advantage of reflective tint, though is that some of the absorbed light heats the window itself and passes that heat back out.

Interior blinds create a convection current around them. They catch the sunlight that makes it through the window, get hotter, cause the air between the blinds and glass to rise, and pull in cooler room air from underneath.

Most modern windows have infrared-reflecting coatings, but it works both ways. If it reflects 90% of the infrared away, 10% gets in. Say you have polished aluminum blinds for 95% reflection, it’s reflecting 9.5% of the original light back to the window. But then the window reflects 90% back again, or 8.5%. Then the blinds reflect again… All the while, it’s finding any gap and heating the materials and air. So yes, blinds help, but it’s best if you can keep the heat outside entirely.

I watch outside air temp closely and do open windows once ambient swings past what I want inside. Problem is, outside hasn’t dropped below 75f/24c in about 5 weeks here. Most of the inhabited world has this issue in the summer unless it’s a desert. Hell, that range is about what I saw in India during winter.