A study by the NIST (National Institute of Standards and Technology) are prompting for the updated facepeices worn by firefighters.
Studies show that modern buildings burn much hotter than older ones. This is putting more stress on the facepeices used to protect the wearer from heat as well as filter the air (which usually has chemicals and toxins during fires). The higher temperatures can begin to melt the facepeices, which can even affect the air filtration. Therefore, these studies have prompted for updated technology to handle the new expected higher temperatures.
For more information, check out the source article below.