Has anyone seen those rollers that you steam before putting in your hair?  a friend has them and I was going to try them because they seem like they might be gentler on the hair than hot rollers or the kind you leave in damp hair until the hair is dry. The thing about the latter is that they take too long, and they always seem to pull the hair too much. Hot rollers seem to be no better than a curling iron, which I won't use on my hair at all.
Anyway, you just put a soft sponge roller on this steamy thing for a few seconds and then roll it into the hair. Then after a few minutes you can take it out. It gets kind of hot but not as hot as the hot rollers.
Kinda cool. I don't do this kind of thing ot my hair that often but every once in a while I want to, so I'm hoping these are gentler than others.

If they don't get so hot as to "steam" or overheat your hair, I would think occasional use would fine.  You don't want them to be so hot that they cause the moisture in your hair to "boil", which would cause split ends.