I would not think this would warrant compensation to be honest. Cabin temperature is a very sensitive subject and we all feel different. Did your friend ask the Crew to adjust the temperature? If asked, I do so myself if possible or,aircraft dependant, ask the Flight Crew to adjust the temperature.
That usually does the trick, unless there was a technical fault of course.
An e Mail to Customer Relations won't hurt, but I guess your friend will get an splogoy and thats about it, unless there was an underlying issue, such as an entry into to tech log, of course.
Without wanting to rant, but this compensation culture really goes a little bit far at times, but then thats only my opinion of course