As I mentioned before, stress causes tangible physical reactions in the body that prepare it for dangerous situations. (wellnessmama.com)
If an otherwise healthy dog starts to turn aggressive, the problem may be an improper diet that is causing physical reactions. (caninejournal.com)
Why is it that eating spicy, «hot» food causes the same physical reactions as does physical heat (burning and sweating, for instance)? (scientificamerican.com)