Any liquid inside a cactus will be highly acidic and likely to cause nausea and diarrhea, further dehydrating you.
Since birds can fly everywhere, and you might end up somewhere that’s even more dangerous than where you started, this one’s definitely a myth.
This is especially important if you’re stuck in a hot place. If you’re thirsty, drink water.
Opening windows or doors can create a powerful wind tunnel that might tear off your roof.
Sharing body heat remains the quickest and safest method to warm someone and treat frostbite.