Is it permissible to wipe over thick, non-transparent socks due to cold, hardship, illness (such as eczema), old age, urinary incontinence, or the need to repeat ablution?

It is permissible for the ill and those afflicted with urinary incontinence to wipe over their leather socks (khuffayn) because the texts concerning wiping are general, and because their purification, in their case, is complete. Moreover, the one in dire need is more entitled to dispensations. Imam Ahmad explicitly stated this.