Mechanisms to decrease heat and allow dissipation

• Behavioural
• Decrease activity
• Vasodilatation
• Sweating: a cholinergic impulse response
• Hyperventilation

Dogs have sweat glands only on their feet, and hyperventilate to keep cool. They hyperventilate dead space, eliminating heat but not ventilating the alveoli, which is why they do not pass out while panting.