**Core Concept**
Temporal arteritis (giant cell arteritis) is a vasculitis primarily affecting large arteries, especially the temporal artery, commonly in the elderly. It is associated with systemic inflammation and can lead to vision loss due to occlusion of the ophthalmic artery.

**Why the Correct Answer is Right**
Temporal arteritis is characterized by inflammation of medium and large arteries, most notably the temporal artery. It predominantly affects individuals over 50 years, especially in the elderly, and is more common in women. It can cause sudden, severe bilateral vision loss due to arterial occlusion. However, it does **not** worsen with heat exposure. The disease is driven by immune-mediated inflammation, not thermal sensitivity. Thus, the claim that symptoms worsen with heat is false and makes it the exception.

**Why Each Wrong Option is Incorrect**
Option A: Temporal arteritis can indeed lead to sudden bilateral blindness due to involvement of the ophthalmic artery. This is a well-known and serious complication.
Option B: It is more common in females, particularly in the 60–80 age group, with a female-to-male ratio of about 3:1.
Option D: It primarily affects elderly individuals, especially those over 50, and is rare in younger age groups.

**Clinical Pearl / High-Yield Fact**
Always consider temporal arteritis in elderly patients with new-onset headaches, scalp tenderness, or visual disturbances—especially if there's a history of jaw claudication or scalp pain. Early treatment with corticosteroids is critical to prevent permanent vision loss.

✓ Correct Answer: C. Worsen on exposure to heat