in hots you have to be a lot more proactive about keeping your army composition correct by getting lots of banelings if they are heavy on the hellbats and roaches if they are actively using widow mines in their army compositions (unless you are very good at baiting their attacks or otherwise minimizing their usefulness)
i also like to have a flock of maybe 15 mutalisks to deal with drops almost exclusively unless im just way ahead for some reason
all the while getting melee upgrades and gradually getting to an infestor/ultralisk composition