I just finished making this purple hat above. I e-wrapped the hat on the adult size loom and just let the brim roll on its own. I only loomed the hat to 6 inches long so that it would fit nicely on a toddler. I then crocheted each of the hearts and sewed them onto the hat. I learned how to crochet the hearts by watching this YouTube video: how to crochet a heart.
This is a very simple hat to create. I hope that it inspires others to try a hat of their own to donate to cancer warriors.