Krynica-Zdrój is generally safe for solo female travelers. Crime rates are low and people are usually friendlier to tourists, but it's still advisable to keep your guard up and stay aware of your surroundings at all times especially at night. Respect local customs and abide by the laws to have a safe trip. Depending on the season, some areas may not have a lot of people, hence increasing chances of isolated incidents. Just like any other location, better safe than sorry, always have emergency contacts handy.