Just a reminder to any allistics: if an autistic friend/family member is having a meltdown, do NOT try to physically hold or trap them *unless* this is something requested beforehand by the Autist. DO discuss with them what is most helpful/harmful. Assumptions are not your friend here. (1/2)
Can I just add that if the person is nonverbal, you still have to tell them what you are doing or offering (like deep pressure if that's something they find helpful) before you do it. They still have ownership of their body. If you don't know them well enough to know what means no, don't touch.
Self-harm in the form of scratching, slapping, punching, and hitting with/against objects isn't uncommon. Unless there is a serious risk of permanent injury, just let it happen. Often trying to stop it will make things much worse and you may end up injured in the confusion. (2/2)