If core body temperature falls significantly below $32^{\circ }C$ (hypothermia), a positive feedback loop can be initiated, causing body temperature to fall even faster. Explain how positive feedback accelerates the process of hypothermia.

Mammals have specialized thermoreceptors, coordination systems, and effectors to prevent such homeostatic failures. Determine whether each of the following statements about mammalian thermoregulation is True or False:

1. Peripheral thermoreceptors in the skin provide an early-warning system by detecting environmental temperature changes.
2. The pituitary gland acts as the main physiological coordination centre that integrates sensory inputs for temperature control.
3. Vasodilation occurs when the smooth muscle in the walls of skin arterioles relaxes, allowing more blood to flow through capillaries near the skin surface.
4. Nerve impulses from the hypothalamus to sweat glands are transmitted via sensory neurones.