About the AC: The same issue happened in Scandinavia 2 or 3 years ago:
Male coworker complain they were sweating because of hot temperature and the obligation to wear uniform long pant whereas they wanted to wear short pant.
Female coworker were at this time allowed to wear dress.
Management refused to listen to the male coworker stating that the long pant was part of the job. Male coworker decided to wear skirt to protest.
Management couldn't forbid them to wear the dress otherwise they could be subject to court claim about gender inequality. So in the end the mangement changed the rules and male can now wear short pants.
The example is kind of extreme and should only be used when ALL negociations fails.
What you and you male coworker do need to do ( in order of importance) :
make a meeting with all the female coworker to officially talk about the situation and try to find a solution ( the company can provide a vest to the female coworker if they are cold, change the desk so female are regroup in 1 part of the office, males in an other part so it is more easy to set 2 differents tempeature)
ask to formal meeting with your bosss to adress the issue and prepare some solution like giving a vest to all female so they are not cold.
write an open letter with a signature of everybody and give it to your boss and upper management.
contact the local union to know if there is a solution
If all the above fail, you can try the following ( but there is risk to get bad reputation/ blame/ fired).
- change set temperature all the time so it will force your boss to adress the issue.
- come to work in short pant and short shirt ( but it should be all the male to do it, not only you).
Regarding the law, of course it depend on the contry, but there is usually only a limit of the "acceptable for health" temperature like 35 degree celcius in the office, there is no "confortable".
In all the discussion and meeting you should ONLY talk about the AC issue, don't talk about other things ( like you boss being only good toward woman) otherwise it would like you want to get revenge on your boss and not solve this issue.