You need to provide your tortoise with daytime temperatures between approximately 75 and 85 degrees Fahrenheit (23 to 29 degrees Celsius). DO NOT keep the tortoise's enclosure warmer than this -- no matter what the pet store may tell you!
People mistakenly assume that sulcata tortoises must be kept at high temperatures because they are desert animals. This is NOT true! When the temperature goes above 85 degrees F, sulcata tortoises will seek shelter from the heat in their underground burrows, and they will stay underground until temperatures drop to tolerable levels. Wild tortoises stay out of the mid-day sun and heat, only coming above-ground to eat and drink early in the morning or early in the evening after temperatures have dropped.
Always make sure that your tortoise has access to cooler areas or shade so that it can cool down when necessary. Nighttime temperatures should be lower than the daytime temperatures, but should not be allowed to drop below 60 degrees Fahrenheit (16 degrees Celsius).
