As I laid in my bed this morning, trying to fend off a migraine, I thought about how much I truly love my reusable ice packs. They remain cold a long time, but they aren't so cold that they are uncomfortable. They are quite malleable and drape nicely over my face or cradle behind my neck. Best of all, they are cheap and easy to find/make.
What are these magic ice packs? A bag of unpopped popcorn, placed inside a freezer bag (because the popcorn bag will break eventually), and freeze. (I also suggest you label it so that the kids don't make snacks out of your ice pack.) If you are fancy, you could make a little fabric sleeve to make it more comfortable, or just slide the bag into a clean sock.
If you have kids, or headaches, or injuries, you definitely try it. These are the best ice packs ever!