"Making a diagnosis of a heat-related death may be quite difficult at autopsy as commonly found features such as skin slippage, pleural petechiae, and pulmonary and cerebral edema are entirely nonspecific [7]. Only very rarely will a core temperature of a body proximate to the time of death be available, and heat often accelerates decomposition which further complicates post mortem assessment [8]."

https://link.springer.com/article/10.1007/s12024-013-9413-y

There was possibly up to 1.5 days of decomposition. My wonderings about the dog was that he was on a leash and possibly may not leave their sides as he knew something was wrong with the infant and adults..best I can come up with.