Dogs in high heat
It can take as little as 15 minutes for a dog to die of heat stroke. Dogs do not have sweat glands, so the only way to regulate their body temperature is to be in the cool, and panting.
Tarmac radiates heat as quickly as it absorbs it. For example, if it’s 20° air temperature, then the tarmac can be 35°. Too hot for a human to walk on, so too hot for a dog to walk on. This will cause blistering and burns to their paws. Meaning expensive vet bills, and not to mention excruciating pain for the dog.