**Cold Temperature Effects**

**Core Concept**
Cold temperature causes vasoconstriction, which is mediated by the sympathetic nervous system through the release of norepinephrine. This results in decreased blood flow to the skin and extremities.

**Why the Correct Answer is Right**
The release of norepinephrine from the sympathetic nervous system causes vasoconstriction, leading to reduced blood flow to the skin and extremities in cold temperatures. This response is mediated by alpha-1 adrenergic receptors, which are found on vascular smooth muscle cells.

**Why Each Wrong Option is Incorrect**
**Option A:** Vasodilation, which is the opposite of vasoconstriction, is not seen in cold temperatures.
**Option B:** Increased blood flow to the skin and extremities is not a response to cold temperatures.
**Option C:** This option is not relevant to the effects of cold temperature on the body.

**Clinical Pearl / High-Yield Fact**
In cold temperatures, peripheral vasoconstriction occurs to conserve heat in the core, but this can also lead to tissue damage if the extremities are exposed to cold for an extended period.

**Correct Answer: B. Decreased blood flow to the skin and extremities.**