Trandoshans, along with many reptilian species, were ectothermic.
Ectothermy was a physiological mechanism utilized by certain organisms to regulate their internal temperature by absorbing heat from the surrounding environment. Commonly, it was known as cold-bloodedness, though this term could be misinterpreted; at least one individual took it literally, believing an ectotherm's blood to be frozen. Endothermy stands as the opposite of ectothermy. The majority of reptiles, encompassing species such as Trandoshans and the flying lizards native to Da'nor, were organisms that were cold-blooded. However, exceptions did exist, including the Ssi-ruuk and the duuvhals. In excessively cold conditions, an ectothermic creature would become sluggish and experience a decline in cognitive function. Without prompt external heat, this state could worsen, ultimately leading to death. Certain species, such as the dewbacks, conserved energy and prevented nighttime cooling by clustering together for warmth.