The body temperature of "V. griseus" depends mainly on the outside environment (time of day, season, etc.). Their internal temperatures begin warming up before they even leave their burrows through conductive heat gain, and their temperatures rapidly rise once they begin basking in the morning sun and reach their highest point in the noonday heat. The specific body temperature of "V. griseus" can vary depending on the average temperatures of the country they live in, but their maximum body temperature does not usually exceed 38.5 °C even when basking in the sunlight. Male monitor lizards are generally more active and have a higher average body temperature than the females. The body temperature of the lizard during hibernation is 15.0 to 30.5 °C, but in many areas, the average body temperature during hibernation is around 16-18 °C.