Both of my kids have seasonal asthma, also hay-fever, not sure if there's a link.
Anyway, If they go near the water October-April it's ear infections, coughs, chest infections and antibiotics after antibiotics.
I try to get them in swimming lessons then May, June, Just the 2 of them in the lesson. I guess my aibu is aibu to expect them to learn in such a short burst?? We do beach trip etc over the summer then and swim for fun. But really it's just intensive lessons for 2 months and then not much the rest of the year......