Is the Human Integumentary System Best Adapted for Hot or Cold

Is the human integumentary system best adapted for hot or cold climates?

A) warm, because sebaceous glands aid us in hot climates but evaporative cooling would kill us in cold climates
B) warm, because sweating cools us in hot climates but we would die in cold climates without clothing
C) cold, because we have many skin features that keep us from overheating
D) cold, because we have a thick hypodermis