Frozen Vegetables

Why is it that frozen vegetables make the best "ice pack" for a sore head? I've been laying around the house for the past couple days with frozen lima beans and frozen broccoli on my head. They just seem to provide so much more relief than the average ice pack, haha! I'm feeling a TON better after surgery. I had my first post-opt appointment yesterday, not so fun, but just thankful to be feeling better today. Getting some rest in today before going to see "mama mia" at the National Theatre with Rick and Laurie.