As you might have heard, heat records are breaking all around the world from the Mediterranean

to South Asia.

Most recently, records fell in the Pacific Northwest and Western Canada.

Across British Columbia, residents are dealing with a record-breaking heat wave.

Seventeen temperature records fell on Saturday with heat advisories sprawling over much

of Western Canada.

This is not a usual May, this is not even an abnormally dry May, this is something exceptional.

A few places saw temperatures in the mid-90s.

For context, that's about 20-25 degrees Fahrenheit above normal.

Today we're talking about heat.

It's nearly summer in the Northern Hemisphere, and with climate change, today's hot summers

will be among the coolest of the rest of our lives.

I'm Scientific American's Earth and Environment Editor, Andrea Thompson.

I'm Kelsal Harper, a Siamultimedia Editor, and you're listening to Science Quickly.

So, Andrea, first things first, how does a heat wave even happen?

Heat waves happen when a high pressure system parks itself over an area for several days.

Under these systems, air sinks, which keeps clouds from forming.

And if you don't have clouds in the sky, that means the sun can really bake the surface.

Imagine getting into your car after it's been sitting in the sun, and you get the picture.

Right, and this can be really dangerous.

In June of 2021, a particularly strong heat wave in the same area contributed to hundreds

of deaths.

...