A snake that lives under the sand
The Kenyan sand boa comes from the dry savannas and semi-desert edges of East Africa, and its whole daily plan happens out of sight: buried in warm sand or loose soil with just the eyes and upturned snout breaking the surface, waiting for prey to wander within strike range. Its temperatures should serve that buried life — a warm end of 90-95°F measured down in the substrate where the snake actually rests, a gradual fall through the 80s, and a cool end around 80°F. Because the snake lives inside its bedding, heat from below suits it well, always on a thermostat, and a thermometer probe buried at the warm end reads the temperature that matters instead of the air above the sand.
Dry is a requirement, not a preference
Keep humidity around 30-40% and be deliberate about it. This is where the sand boa most often gets into trouble in captivity: a keeper reads that boas need tropical moisture and mists an enclosure whose occupant evolved for arid ground. Chronically damp, still air over wet substrate is the standard prelude to wheezing respiratory infections in this species, and persistently wet bedding encourages skin problems on a belly that never leaves the ground. A small water bowl at the cool end is all the moisture infrastructure it needs; if the bowl is big enough to raise the enclosure's humidity noticeably, it is too big for a sand boa.
Sand, depth, and the nightly emergence
Give the snake three to four inches of suitable loose substrate — play sand, a sand-and-soil mix, or fine aspen are all used — so it can bury itself completely at its preferred depth and choose its layer by temperature, warmer or cooler as it wishes. Activity is the keeper's best health gauge: a settled sand boa emerges toward evening, cruises the surface with clear eyes and steady tongue-flicks, and takes food from the sand's edge with enthusiasm. One that lies exposed on the surface all day, refuses food for weeks with temperatures verified, or breathes with a wheeze or visible mucus needs a reptile vet, since surface-sitting in this species usually means the buried world has gone wrong somewhere.
The shed exception and the written record
The one time added moisture helps is a shed: when the buried snake's colors dull and its eyes cloud, a small humid hide or a lightly misted corner for a few days lets the old skin come away cleanly, after which the enclosure goes straight back to dry. Outside that window, more humidity is never the fix for a sand boa problem. These settings are so contrary to generic boa advice that they are worth fixing in writing — entering the warm-end, cool-end, and humidity figures into your Kenyan sand boa's KinsLe Pet Passport keeps its records and its arid-climate requirements together, ready for a vet visit, a sitter, or a future owner to follow exactly.