No, maybe they aren't at physical risk for actually being burned ... but they are concerned about the amount of heat. They have a problem, whether you agree with it or not.
Years ago my sister was worried about plastic baby bottles harboring germs and was desperately looking for glass bottles. Glass is actually more porous than plastic, but since neither are inherently bad did I go and try to convince her otherwise? No, I helped her find glass bottles. (Oh, and I would have been faulted, in real life, for telling my sister that there were no problems with plastic baby bottles!)
Feel free to offer your advice, wisdom, experience and solutions, but it will behoove you to not take offense if someone chooses not to listen.
@T35RK ... my handset does get quite toasty. I'm not concerned about my skin and being burned, but I am concerned about the health of the battery at the higher temperatures. I am also monitoring the thread for an answer!