Okay... You'll be fine swimming in that, I think. Oh! But you'll want to grab a towel or something to dry off with once we're in the dungeon, or you'll freeze to death like Toki almost did when I took him.

[ Either something to make fire or a change of clothes. If they're lucky to go from the lake directly to the third floor in the forest, it'll be raining but not freezing; if they're unlucky, they'll skip to the second floor with the arctic wasteland and Yamato will freeze in three seconds. ]