Interesting. My autistic daughter (who also has PTSD) and autistic grandson both need heavy covers when sleeping. As we are now in the tropics, daughter has special weighted covers which are heavy however not hot. Also both daughter and grandson wear weighted vests when needed, to stay calm and focused. Grounds them apparently, helps with sensory integration issues. Makes them more aware of their bodies in general. One wonders if it would help some PTSDs as well - especially those with dissociation problems. Jim.