Do clothes become ritually impure (najis) by sweat if urine has dried on the body of a child suffering from enuresis, and does a chair or car seat become ritually impure if he sits on it and sweats?

The clothes of a person are not judged to be impure unless it is known that they came into contact with an impure place while wet or damp. Doubt about the transfer of impurity does not render the clothes impure. Whatever his clothes touch from pure things remains pure. The child should wash the impure area when changing his clothes to ward off obsessive thoughts and should consult doctors.