If you aren’t getting enough fresh air to the lungs, you will know it, because you’ll pass out.
Police say excessive wearing of N95 mask contributed to driver passing out, crashing car!
3 years ago in the fall, we had the horrible fires over N. California, and our FP recommended buying the N95 mask when going outside due to the smoke that didn’t clear.
We found out very quickly on our regular walks, going up any hill, it was difficult to breathe properly.
Also,they were so effective in blocking incoming particles the outside of the masks after about an hour outside were covered with soot.
Then, when we took off the masks, the insides were covered with our snot, again in about an hour’s use age outside.
Tricky to use and probably not great for outdoor use age.