Weak person working in fire stations can't handle strain (6)

I believe the answer is:
softie
'fire stations can't handle strain' is the definition.
I can't judge whether this defines the answer.
'weak person working' is the wordplay.
'weak' becomes 'soft' (similar in meaning).
'person working' becomes 'ie' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'soft'+'ie'='SOFTIE'
'in' acts as a link.
Can you help me to learn more?
(Other definitions for softie that I've seen before include "Milksop" , "Weakling" , "sentimental type" .)
