Again this problem.
Opera 42.0, Macbook Air 11 early 2014.
The laptop gets hot while using Opera, the activity monitor shows huge numbers of CPU usage (up to 90-130 % CPU) either for Opera or Opera Helper processes (or both), especially while using Adobe and its products (adobe connect, flash, etc.). Sometimes just for no (visible) reason.
The problem started about 2 months ago, I have no clue what version of Opera it was, but it still remains and consumes my battery in huge amounts, plus melts my table and everything where my superhot laptop is (the insides are clean, seems not to be the dust problem).