JACKSON, Miss. (AP) — Mississippi dispatchers are fielding desperate calls for medication or oxygen from people stuck in their homes. Troopers in Tennessee are fanning out for welfare checks on those who haven’t been heard from in days. And in at least one rural area, officials have resorted to using trucks typically used for battling wildfires to transport patients to hospitals. It could be days before power is restored across the South, where more subfreezing temperatures are expected by