I have bought several of these this past year. We used these when working with lye, sulfuric acid and hydrogen peroxide 30%.
I like the blue b/c I know they are mine as opposed to the all yellow gloves that were bought previously. They do help resist the heat and the XL is great for some of the bigger students (16-17 yr olds) that I teach. They are too big for my hands but these gloves fit them quite well.
I was so excited when HST started carrying this size. I've used their gloves in my chemistry lab for years and they have held up well. Every once in a while I get a student with XL hands and it was near impossible for me to find suitable gloves for the student. Now HST makes it possible for me to glove all my students properly!