+1 on more clothing, like Shug said. I find adjusting my clothing gives me +/- 10 degrees or more (depending on wind, humidity, etc.) on my insulation. Throw a fleece on top (or a lightweight down or synthetic top), plus a warm hat, and you'll be comfy in the same conditions next time.
"We do not go to the green woods and crystal waters to rough it; we go to smooth it." -- Nessmuk