Just, wearing something that necessitates a completely airtight seal for an extended period of time (just one of a hundred reasons people with prosthetic limbs don’t wear them long periods generally)
Another interesting fun fact too is that biologically, our hands play a massive role in thermoregulation in the body, and losing even one makes it that much harder to regulate one’s one body temperature!
Also interesting, phantom pain stuff, which is a VERY fascinating physiological thing (proprioception in general is a very complex, extremely fascinating thing imo) and extremely common, especially for the first several years
Which is like, largely just your brain sending signals to a limb that isn’t there and getting no feedback and deciding that it’s paralyzed or in danger
And i guess a easy and common line of “treatment” is just, tricking your brain with a mirror into thinking you have your missing limb which is very funny.
(ANOTHER fun fact is that this works in reverse....you can trick someone with two hands into thinking a fake hand is their own and can “feel” sensation; the famous rubber hand illusion)