@bronchiectasaurus I will add that there are vented N95 masks that make inhaling/exhaling during exertion or in hot/humid weather easier. I cannot mow/weed whip or other heavy exerting in the plain N95 mask, but these work for me.
Here is what we use:
https://www.durawear.com/3m-particulate-respirator-8210v-with-valve-n95-two-strap-design-cushioning-nose-foam-box-of-10-each/
Available from a variety of sources.