Okay, let's tackle this question. The question is about central fever and its characteristics. The task is to figure out which option is the exception.

First, I need to recall what central fever is. Central fever, also known as neurogenic fever, occurs due to dysfunction in the hypothalamic thermoregulatory center. This is different from peripheral fevers caused by infections or inflammation. Common causes include head trauma, brain tumors, or stroke affecting the hypothalamus.

The key features of central fever are that they don't respond to antipyretics like acetaminophen or NSAIDs. They are often associated with a lack of chills and sweating, and the fever is usually low-grade. Also, the temperature elevation is typically not accompanied by an elevated white blood cell count, which is a sign of infection.

Now, looking at the options, the correct answer is the one that doesn't fit these characteristics. For example, if an option says the fever responds to antipyretics, that would be incorrect because central fever doesn't respond to them. Another incorrect point might be the presence of chills, which are absent in central fever. Also, if an option mentions infection as a cause, that's wrong since central fever is due to CNS issues, not peripheral infections.

I need to make sure each incorrect option is addressed properly. The clinical pearl would be to remember that central fever is non-infectious and unresponsive to standard antipyretics. The correct answer is the one that contradicts these points.

**Core Concept** Central fever (neurogenic fever) results from dysfunction of the hypothalamic thermoregulatory center due to CNS lesions (e.g., trauma, hemorrhage, tumors). It is distinguished from peripheral fever by the absence of immune/inflammatory mechanisms and lack of response to antipyretics.

**Why the Correct Answer is Right** The exception is **Option C**: "Responds to antipyretics like acetaminophen." Central fever arises from direct hypothalamic disruption, bypassing the endogenous pyrogen pathway. Antipyretics inhibit cyclooxygenase enzymes (COX-1/COX-2), which are irrelevant here since central fever lacks prostaglandin-mediated hypothalamic resetting. Treatment involves addressing the underlying CNS pathology or using physical cooling.

**Why Each Wrong Option is Incorrect**
**Option A:** "No chills or sweating" is correct—central fever lacks autonomic responses like shivering due to hypothalamic dysfunction.
**Option B:** "No leukocytosis" is correct—central fever is non-infectious and does not trigger neutrophil release.
**Option D:** "Low-grade temperature elevation" is correct—fever is typically mild (≤39°C) and persistent, unlike the spikes seen in infections.

**Clinical Pearl / High-Yield Fact** Remember **"CNS fever = no drugs, no chills, no white cells"**: Central fever does not respond to antipyretics, lacks autonomic thermoregulation, and is non-infectious (no leukocytosis). This differentiates it from sepsis or viral infections.

**Correct Answer: C. Responds to antipyretics like acetaminophen**

✓ Correct Answer: C. Decreased response to external cooling