Do blackout curtains keep heat out? Our HVAC experts reveal everything you need to know

A cream and green living room with a mirrored wall, large mantelpiece with colorful artwork above, two matching cream couches with green cushions and a green coffee table between.

With heatwaves sizzling, you might be wondering, do blackout curtains keep the heat out? Luckily, the answer is yes.

Both blackout and thermal curtains have been praised for their ability to keep a home warm in warmer months, and, it turns out, they work just as well to keep a home cool in a heatwave, too.