Heatwave in Seattle ... blah blah blah ... but I did learn about measuring temperature via the "wet bulb" method. Basically it is a measure of how well your body can cool itself through perspiration at various temperatures/humidities. Most human beings cannot function when the wet bulb temperature is between 90-95 degrees Fahrenheit, or 35C. Which is where you die, because your body can't sweat to cool itself down.

It was 113 here two days ago. I can't seem to find the WBGT (wet bulb globe temp) for the last three days here in Seattle, but we were apparently well within the death-zone, with greater than 60% humidity and air temps in the hundreds. (WBGT is measured in the sun. Heat Index is measured in the shade. So they are very different.)

And now you know a bit about wet bulb temperature measurement. The wet-bulb temp is a thing I think we 'normal people' will need to know and track pretty closely over the next 20-40 years. When I was a kid, nobody heard or cared about UV indexes or pollen counts or air quality indexes. *(Even in LA in the 1970's. There were just days where we were supposed to stay indoors, because the air outside was "bad". Like... where did they think the air indoors came from...?)*

I suspect the grandkids being born today will track wet bulb like we track pollen counts.