I wonder how it fares actually cooling the body. Does the fabric also block heat coming from the body wearing it? Has anyone information on the fabric that was

I wonder how it fares actually cooling the body. Does the fabric also block heat coming from the body wearing it? Has anyone information on the fabric that was able to cool the body that Ars covered? https://arstechnica.com/science/2021/07/new-fabric-passively-cools-whatever-its-covering-including-you/ https://arstechnica.com/science/2021/07/new-fabric-passively...