Start with measured reference ranges
The Royal Veterinary College gives 21–23°C and 75–90% relative humidity as broad care guidance for giant African land snails, while warning against temperatures below 18°C or above 29°C. These are useful reference points, not permission to ignore species-specific information.
Ask the breeder for the scientific name and the conditions in which the animal has been raised. Avoid making sudden changes simply to hit a number you have found online.
Measure both temperature and humidity
Use a digital thermometer and hygrometer positioned where they reflect the snail’s living area. A minimum/maximum thermometer helps reveal overnight lows and daytime peaks that a quick reading can miss.
Check the instruments against another reliable device occasionally. Cheap gauges can drift, and a reassuring display is not useful if the reading is wrong.
Heat safely
If room temperature is not sufficient, use an external heat mat controlled by a thermostat. Positioning should create a gentle gradient so the snail can move away from the warmer area. Never place the enclosure in direct sunlight or against a radiator; both can cause rapid, uneven overheating.
Heating changes humidity, so adjust one variable at a time and monitor the enclosure after every change. Cables and electrical equipment must remain outside the snail’s reach.
Manage humidity without waterlogging
Mist with clean water as needed, keep the substrate damp and provide a very shallow water dish. Ventilation is still necessary: permanently saturated soil and stagnant air are not the same as healthy humidity.
Condensation alone is not an accurate humidity measurement. Use the hygrometer, feel the substrate and watch for mould, persistent dryness or a snail repeatedly sealing itself into the shell.
Respond to change calmly
If readings move outside the intended range, correct conditions gradually while checking for a simple cause such as an open lid, dry substrate, failed thermostat or unusually warm room. Persistent inactivity, tissue changes or failure to respond after conditions are corrected warrants advice from an exotics vet.