Adaptations that everyone knows about are common hah, are you okay with only knowing what commoners know, you will become a rare person after reading this *spoiler*.
YES flamingos, big pink fluff bags that everyone liked as little kids but forgot about when they turned 10. These birds are super rare because they can survive on, yeah I know, DEEEP BREATHS; salt water and boiling water! These birds have a special ability similar to that of an anime character to eject salt from their bodies, and they can endure boiling hot water going into their throats. Let me go and check if I have this adaptation; OOOOOOOOUUUUUUUUCHHHHHHHHH, WHHHHHHHYYYYYYYY?????? Am I not a flamingo?!?! Clearly not.
Some animals that survive because of their fat are seals, which are cute animals that almost every little kid has at one point thought of calling their "Munchkin". These abnormally, nay, almost creepily cute animals can survive the freezing temperatures of the Arctic and Antarctic Oceans because they have lots of blubber. This time I will not try dumping myself in freezing cold water, but I will let my fellow humans in the Arctic give it a go. Well, evidently they already did that, so here goes...
Paul (2010 - 2023), died from indigestion, boiling water, while sitting in a frozen pond for science.
Now you are officially a rare human traumatized by my death :D. Here are a few other adaptations I did not test, hibernating over winter (this would have been fun) and growing claws on my feet for climbing mountains (😭 I wish).