Colibri,
It is no wonder that you might find a helmet uncomfortable if you get so hot under the collar about what is at the moment a hypothetical discussion. I think the too hot and uncomfortable argument would get shot down fairly easily since, as has been said here before, there are pilots who have to wear a helmet flying in hotter (in every sense of the word) conditions.
I happen to agree that wearing a helmet in the offshore environment is a bit over the top. Head protection is better provided by other safety measures such as SOPs, modern aircraft, training etc. Birds don't seem to go through windows very often. The only scenario I can see where helmets would be introduced is the noise issue and I am dubious if that can be justified. However if helmets are deemed necessary, the solution to sweaty heads is simple - air conditioning.