That's what they told us in the lab, that it wouldn't hurt until later. Tissue doesn't stop it, your flesh erodes to the bone. If you are burned over a large enough area, it will mess with your calcium metabolism and cause cardiac arrest. The first aid treatment these days is apparently a water rinse and calcium gluconate gel, but I seem to remember sodium thiosulfate solution being pulled out to have standing by. Of course that was 35 years ago, and I've slept since then.I hear it anesthetizes as it burns. Yeesh.