Why is Ivy Bridge so hot and bothered?

If you read our Ivy Bridge coverage carefully, you'll know that we observed some rather high temperatures when overclocking the Core i7-3770K. With a single-fan air tower, our chip ran at a reasonable 50-60°C when clocked to 4.4-4.5GHz at its default voltage. However, when we pushed to 4.9GHz on 1.35V, the temperature soared past 100°C. Other reviews have observed similarly scorching temperatures, so it's not just our sample.