Thanks so much for the advice, ladies. It is good to know that there are others out there struggling with the same issue (DS is the only one out of his friends who refuses to wear a hat and it often makes things difficult at Mums group, especially if we all spend a fair bit of time outside). I told DH that he needs to wear a hat too and we plan on leaving them at the back door and never going out into the garden without putting it on. Hopefully DS will catch on. Tomorrow is the day we start the hat challenge. I am trying to muster all the determination to win this battle. Thanks you all again for taking the time to reply.