Feels one would be mad to be out of them (6)
I believe the answer is:
senses
I believe this is a double definition.
'feels' is the first definition.
('sense' can be a synonym of 'feel')
'one would be mad to be out of them' is the second definition.
(as in being 'out of one's senses')
(Other definitions for senses that I've seen before include "'Hearing, touch etc. (6)'" , "Faculties for experiencing the world" , "We have five, though some claim six" , "Touch and taste, e.g." , "Feelings" .)