KARACHI, Pakistan The ongoing cold weather flanked by heavy snowfall has put 270,000 children in Afghanistan at "serious" risk of contracting life-threatening illnesses, the UN Children's Fund (UNICEF) warned on Thursday. The UN agency, in a statement, said heavy snowfall has worsened the already critical situation for children affected by last year’s earthquake in eastern Afghanistan as freezing winter temperatures deepen an already dire humanitarian situation. Prolonged exposure to cold and