SM has this one right I have had quite a number of rescues come though (on the board of rescue organization) The new rescue is often suffering from neglect and or abuse. They really need perfect husbandry and unless there is something pressing piece and quiet. Stress is a huge issue and typically they are stressed to the max. During my advanced animal emergency first aid course I did the term used was 'skillful neglect' Meaning if there is no great threat and basically the animal is in ok health just let it be.
Fresh water and humidity are important and correct temps CRITICAL. I often keep the enclosure in the dark way out of the way (closet works really well).
Remember do not use anything that will contact your snake. No tools your hands nothing I use a completely new set of duplicate tools that are tossed or go with that snake when forever homed. I scrub my hands before and after touching anything near the rescues enclosure. ideally in a different room if not as far as possible away. I keep this up for at least 6 months. No cross contamination. I also isolate the rescue with a bed of diatomaceous earth. QUARANTINE!!!