faint estuary
PS.: Don't know if this is already a think on vanilla, if yes, ignore this post.
Basically, if the difficulty is on hard, when the player is in a cold biome if a blizzard (equivalent of thunderstorm in icy biomes) happens and the player/mob is "outside" (dunno how "inside" can be considered - perharps if the player is directly under the sky without a block over it, or using an variant of the logic villagers use to determine if they are on a house) they start to get Freezing damage, just like when submerged in powder snow.
ember bear
indigo kelp
exotic loom