As Giant African Land Snails are originally from a tropical climate, they should be kept at around 20-29 degrees celcius (68-84 fahrenheit), but no more than this.
If the tank is in a cold room, a heat mat can be used to maintain the temperature of your snail's habitat. Many people use heat mats throughout the winter as well. Heat mats should be attached to the side of the tank, rather than sit underneath, and it should cover around half of the side of the tank. This is so that there are cooler areas for your snail to escape to, if it feels too hot. Insulation should be placed on the other side of the heat mat, and underneath the tank to stop the heat from escaping. Polystyrene is best for this, but you can also use bubble wrap or towels.
Snails should be kept out of direct sunlight, so don’t try and heat the tank up by placing it on a windowsill.
If the temperature or humidity of your tank falls outside the recommended ranges, your snails might start to hibernate or aestivate.
Giant African Land Snails also like humidity, so spraying them with water every day is important. Achatina fulica prefer less humid conditions to other snails, so don’t get them too wet. Humidity is best at around 75-90% percent and you can check this using a small hygrometer. Dual thermometers/hygrometers are also available and are very useful for keeping an eye on the temperature and humidity of your snails' habitat. Both digital and analogue thermometers/hygrometers exist, and both are fine to use for snails, although many people prefer digital ones as they tend to be more accurate.