There is a clothing product you can purchase from Dynamic Orthotic Systems for kids who need extra pressure to help them throughout the day. It is called SPIO which you can read up on at http://www.spioworks.com/. Basically it's tight breathable clothing which can help calm down a child. Sometimes even with state insurance it can be gotten for free or even a very low cost if your doctor will write a prescription. They I believe even have a trial period in which you can try one and see if it works for your child because every child processes things differently.
Anyhow, some of our insurances won't cover it and others of us can't afford it so what are some other options? One thing that was suggested to me is two piece swim suits a size smaller (for girls you might want to do the tankini rather than a swim top that doesn't stay snug to the upper body). Another thing to try is exercise type spandex clothing which once again may need to be a size smaller. Either of these things can be put underneath clothing if the attire is not appropriate for running around... like now. Day time options for girls can also be leggings or tights for pants which can also be purchased a size smaller.