Two suffering with heart trouble (3,5)
I believe the answer is:
hot water
'trouble' is the definition.
(to get in hot water is to get in trouble)
'two suffering with heart' is the wordplay.
'suffering with' indicates anagramming the letters.
'two' mixed up with 'heart' gives 'HOT WATER'.
(Other definitions for hot water that I've seen before include "Trouble (if you're in it)" , "Distressing plight to be in" , "Difficulty" , "Kind of trouble, could be scalding" , "Predicament to be avoided (informal)" .)