Most of us just kind of know what we wear in the heat can affect how hot we feel. Yet, it's not something I think most of us have thought about all that much. At least not beyond asking ourselves whether we should wear a dress shirt or a polo shirt. Shorts or Jeans. Slacks or a dress. Yet, the National Weather Service Office out of Kansas City did a little test during the heatwave we just experienced that shows exactly the best type of T-Shirt to wear when it's hot.

The NWS staff took three types of T-Shirts and placed them outside in the sun. The T-Shirts included a white cotton T-Shirt, a black cotton T-shirt, and a white polyester T-shirt. So which one do you think would be the coolest to wear?

I would have put my money on the white cotton T-shirt. I mean, it's pretty easy to know that even though you'll look the coolest in the black T-shirt, it's just going to soak up the sun. Plus, cotton is natural, so the white cotton T-Shirt is the one that'll be the coolest, right?

Wrong.

The white polyester T-shirt stayed the coolest. At 2:30 PM CDT, when the air temperature was 97, the black T-shirt was 24 degrees warmer than the air temperature. The white cotton T-shirt was 16 degrees warmer than the air temperature. While the white polyester T-shirt was only 11 degrees warmer than the air temperature.

The white polyester T-shirt also didn't heat up as quickly as the white cotton or the black cotton T-shirts. At 9:30 AM CDT, the first time the NWS measured the temperatures of the shirts, the white cotton, and white polyester T-Shirts were 88 degrees, while the black T-shirt was already five degrees warmer.

So does the NWS test hold up? First, I didn't bother to prove that a white or light-colored T-shirt is better than a black or dark colored T-shirt. I've proven that to myself just out walking around the Missouri State Fair, and I bet you have too. What I did want to look up is whether others thought polyester T-shirts were actually better.

It was hard to find proof because most of my search results were trying to sell me a T-shirt. Yet I did find a story from Outside Online that proved the NWS test. Outside Online says cotton shirts aren't bad, but that polyester is better:

Most polyester-based knits let moisture evaporate quickly, giving you lots of cooling when you’re active and keeping you dry once you’ve found a shady place to sit and rest.

This doesn't only prove the NWS test which was just proving how warm the T-shirt actually gets, but how it performs when the shirt is being worn. Interestingly enough, in a climate like Missouri, when it gets really hot and you're outside and active, there may not be a really good solution. "If you’re facing a climate that is both hot and humid, nothing is going to work that well. In that case, I’d suggest a synthetic shirt—at least you’ll stay a little bit drier than you would in cotton."

So there you have it, a polyester white T-shirt is best to wear when you're outside in the heat. Or perhaps, it's a better choice to just hang out in the air conditioning and binge-watch one of your favorite TV shows. Here's the results of the test performed by the National Weather Service in Kansas City posted on Facebook:

LOOK: The most expensive weather and climate disasters in recent decades

Stacker ranked the most expensive climate disasters by the billions since 1980 by the total cost of all damages, adjusted for inflation, based on 2021 data from the National Oceanic and Atmospheric Administration (NOAA). The list starts with Hurricane Sally, which caused $7.3 billion in damages in 2020, and ends with a devastating 2005 hurricane that caused $170 billion in damage and killed at least 1,833 people. Keep reading to discover the 50 of the most expensive climate disasters in recent decades in the U.S.

KEEP READING: Get answers to 51 of the most frequently asked weather questions...