[header] How to deal with autistic children's meltdowns [title] Act in a calm and reassuring manner. [step] During a meltdown, the child may feel confused, agitated, frustrated, overwhelmed, or scared-i.e. experiencing all sorts of negative emotions. [substeps] Therefore, shouting, yelling, or hitting them will do nothing to help in this situation. 
It is far more likely to aggravate the situation. During a meltdown, a child most needs the opportunity to relax.