The World Federation One Stop Fiqh

Ruling 258

Wiping performed on socks or shoes is invalid. However, if one is unable to remove his socks or shoes on account of severe cold, or fear of thieves or predatory animals etc., then the obligatory precaution is that after he has wiped on his shoes or socks he must also perform tayammum. If it is a matter of taqiyyah,26 it is sufficient if he only wipes over his socks or shoes.

26 Taqiyyah refers to dissimulation or concealment of one’s beliefs in the face of danger.