With a flushed face, no doubt, and a rash (3-6)
I believe the answer is:
hot-headed
'rash' is the definition.
(I've seen this before)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for hot-headed that I've seen before include "Impetuous, quick-tempered" , "Impetuous, rash" , "Impulsive" .)