Increase in ability to sweat

Do saunas increase your ability to sweat outside of being in one, for example when I first started using a sauna I didn't sweat much during my workout, after using the sauna 4 times a week for a month my sweat amount during working out and just in general has increased, does the sauna activate sweat glands that were dormant? Or does it open pores to sweating more, I'm trying to figure this out