I'm thinking about foam in ear plugs rather than the molded variety, they expand to fill the ear nicely and seem quite comfy. The molds are just for sets which have ear hooks rather than a band aren't they? I work as a broadcast sound supervisor and haven't heard presenters complain of hot ears from their ear molds - we're all different.
What make of in ear did you try?
The bose x are obviously very good but very expensive for someone just starting out - and they only really work as ANR sets, their passive noise reduction isn't that good is it? - not a problem if the battery is kept charged or they're plugged into the aircraft power. Their ANR is the best I've heard.
The Pilot's are a more affordable venture into ANR for a new student pilot.
But the HM's should do him for now, unless he's flushed.
I agree that DC's are overated - their main appeal to instructors seems to be that they won't break if you sit on them.