What is Islam's position on some people's supernatural abilities, such as enduring extreme cold or not bleeding from stab wounds?

Allah built the universe upon fixed laws. Allah may break the norm either as a miracle for a prophet, or a charism for a saint, or as a way of gradual leading astray and a trial for a wicked person or a disbeliever. Magic is one of the extraordinary phenomena that can be learned and undone. Some extraordinary phenomena may occur at the hands of polytheists and wicked people due to the jinn accompanying them, so they perform acts akin to magic. There are things thought to be extraordinary, but they are in reality optical illusions achieved through learning. Therefore, one should not be deceived by extraordinary phenomena; rather, one must look at a person's life and uprightness.