Wrestle madly and suffer in heat (7)
I believe the answer is:
swelter
'suffer in heat' is the definition.
'swelter' can be an answer for 'suffer' (sweltering is a kind of suffering). I'm not sure about the 'in heat' bit.
'wrestle madly' is the wordplay.
'madly' is an anagram indicator.
'wrestle' is an anagram of 'SWELTER'.
'and' is the link.
Can you help me to learn more?
(Other definitions for swelter that I've seen before include "Be uncomfortably hot as in the sun" , "Overheat" , "Sweat and feel faint" , "Be too hot; Gormenghast chef" , "Suffer when too hot" .)