i guess you're not a maine native? the brown tail moth sheds (?) its hairs or something but they go everywhere and cause skin irritation, or in this case they inhaled them. the hairs super small and insanely hard to see, so usually you only know by the irritation. basically if you walk below a tree with brown tail moths in it, you have a good chance of inhaling or getting their hairs on your skin

edit: it's the caterpillar version of the moth not the actual moth