Thread by @ktwatkins

🧵.@sarawilla1 and I spent the summer investigating the impact of extreme heat on @METROHouston riders. Here's what we found...

It started because we kept seeing riders waiting for the bus ~behind~ bus shelters. Then we heard people describe the shelters as "Easy Bake Ovens," "hotboxes," "steamy." We wanted to see just how hot they were getting...

To do that, we got a thermometer that measures ~wet bulb globe temperature~. Experts say WBGT better captures the impact of heat stress on the body because it takes into account factors like solar radiation, wind & cloud coverage in addition to air temp & humidity.

Expect to see a lot more of WBGT in the coming years. Meteorologists like @mattlanza & Tim Cady w/ @NWSHouston say they see it as the heat metric of the future.

After we got our high-tech thermometer, we took temps inside bus shelters, in direct sunlight & in any nearby shade (like under a🌳) if available.

We crunched the data & found:
1) 73% of temperature readings inside bus shelters reached thresholds that put people at “extreme” risk for heat illness.
2) Temps inside bus shelters averaged 91.4° WBGT -- above the "extreme threat" threshold for heat stress risk in Houston.

And bus shelters were inconsistent at cooling riders:
* Temps inside bus shelters were cooler than direct sunlight in 60% of our readings
* But in some cases, bus shelters made the heat worse -- it was hotter inside the shelter than standing outside in direct sunlight.

The hottest temp we recorded inside a bus shelter was 103 WBGT. It was 8° hotter ~inside~ the shelter than standing outside in direct sun. (More on why we think that happens in our full article: )houstonpublicmedia.org/articles/serie…

Keep in mind we took temps during some of the hottest weeks of the year. But riders will be increasingly exposed to extreme heat as climate change makes longer heatwaves and hotter temperatures the new normal in Houston.

“Transit riders are at the front lines of the heat and climate crisis,” says Gabe Cazares w/ @LINK_Houston “Too many METRO stops lack shade or shelters. Every minute waiting for the bus is a minute exposed to the elements.”

And we heard from riders who have experienced symptoms of heat illness: headaches, dizziness, skin irritation & in the most extreme case passing out.

There was one✨superstar✨in our readings though: 🌳shade:
1) 100% of tree shade readings reduced temperatures.
2) Trees were on average 5.6° WBGT cooler than direct sunlight.
3) Tree shade rarely entered the extreme risk for heat stress category, averaging 87.1° WBGT.

So what could some solutions look like? Urban planner @christofspieler says there's no silver bullet. "It’s a lot of little things added together," he says. Things like increasing bus frequency & reliability and adding more street trees and shaded shelters.

We'll dig more into solutions in our 3rd episode. For now, all of our data and the first two podcast episodes are available here: houstonpublicmedia.org/articles/serie…

And we really want to know what you think of our findings! Fill out our survey here: docs.google.com/forms/d/e/1FAI…