Our Lady of Guadalupe, the church with the crown in PV is a nice place for mass but it is not air-conditioned. It is a pretty brick and cement building that once full of sweaty people loses some of its charm. If you go here sit in the very back pews towards the center isle and pray for a breeze.
Our Lady of Peace, the church in Bucerias is smaller with trees and open windows. I would still sit in the back and pray for a breeze.
Another good thing about sitting in the back is you could leave without bothering anyone. To stay in back means ignoring the people that want you to move down, get up and let them through but keep your spot.