Bearded dragons like it HOT! The key to heating your vivarium enclosure is providing a temperature gradient from a hot basking zone, to a cooler area. Basking spot temperatures/temps should reach around 105°F (40.5°C) to 115°F (46°C), with the surrounding hot zone approximately 95°F (35°C) and the cooler zone should be around 85°F (29.5°C).
Night time temperatures should not fall below 65°F (18.3°C) and best kept around 65°F (18.3°C) – 70°F (21°C). Its more important to keep good warm temperatures for a young bearded dragon than it is for an older one.