It should hold up ok, but a bag or towel would not hurt.
The K1000 was my main camera when i shot horse show jumping with film, and i did a few in so so bad weather. It lived.
A lurker over at PDML, and a one time GFM speaker, uses a small towel an puts it over lens and body. He does a lot of his nature, flower work in foggy and wet weather, and it works for him.
I once had a SP500 go for a swim in the Pacific ocean, off of the Queen Charlotte Is in BC Canada, in 1975, and it finally needed a CLA in 1994.
Dave