If core body temperature falls below $35^{\circ }C$ (hypothermia), a positive feedback loop can be initiated, causing body temperature to drop even faster. Explain how positive feedback accelerates the process of hypothermia.

Mammals utilize specialized thermoreceptors, effector mechanisms, and coordination centres to prevent such homeostatic failures. Determine whether each of the following statements about mammalian thermoregulation is True or False:

1. When core body temperature falls, arterioles supplying skin capillaries constrict while shunt vessels dilate.
2. Hair erector muscles contract to trap a layer of still air, which acts as a good thermal conductor to accelerate heat loss.
3. The thermoregulatory centre in the hypothalamus sends motor nerve impulses to effectors such as skeletal muscles to initiate shivering.
4. Negative feedback loops act to amplify any deviation from the physiological setpoint to restore baseline conditions.