DONT LEAVE YOUR HELMET ON WHILE NOT MOVING
i have a habbit of just stopping for a min to take a sip of water, or to scout a tight riding area, and leaving my helmet on.
all the heat radiating off my body, and from under my shirt, and me breathing hot air right into my helmet, makes for very hot breathing air.
and personally, i say fewer breaks.
just take quick water breaks and be moving as soon as possible
that wind is what lets me stay out all day, the minute i stop moving, i like overheat.