It's a wrap.

Let's play sausage roll he declared.

Tom likes to be rolled tightly in his duvet and then patted. This brings him a sense of calm and well being. Along with a lot of giggling.

For anyone who has seen the film Temple Grandin about the autistic doctor of animal science, this is a similar effect to the one she gained from her "squeeze box" or hug machine, minus the giggling I think.