I think if you started with a regular shirt, and then put this one on instead, you would eventually start cooling down. The article says that human skin radiate

I think if you started with a regular shirt, and then put this one on instead, you would eventually start cooling down. The article says that human skin radiates in MIR but that's blocked by normal fabric. So if you take off your shirt, you will radiate more, and possibly cool down a bit. This fancy shirt is similar to not wearing any shirt, except it can also reflect visible light a bit better because it's whiter. It might even be more efficient at radiating MIR than skin? I'm not sure, but if it's better than normal fabric it should help. Obviously the physiology here complicates things, but it really could cool you down- your body is always attempting to radiate way heat, and this is supposed to make that process faster. It's like carrying around your own shade.