Doctors and homeless advocates say the feet suffer the cruelest fate of life on the streets. Spending day after day in wet, sweaty or soiled socks leads to fungus, bacterial infections and gangrene. Wearing no socks or plastic bags hastens diabetic neuropathy and frostbite. "The feet are a portal to the rest of the body," explains Kathya Zinszer, chair of Temple's School of Podiatric Medicine, who runs clinics at area homeless shelters.