There are no specific requirements to becoming a PT tech. Do not trust the television ads that you see saying you can get a degree in PT tech. The job does not need any special education requirements. In some places a PT tech is also called a PT aide. Realize that these are equivalent. This is not a licensed profession and anyone can be one. Some facilities may have their own requirements, however. Many clinics only hire PT students as technicians in order to give them some experience in the field.
This differs from a PT assistant. Becoming a PT assistant requires an associate's degree that involves at east 2 years of school. To become a physical therapist you will need a 4 year college degree and then either a master's or doctorate in physical therapy.
I know this is more info than you asked, so in short: you need to speak well, have proper grooming and people skills, and be able to follow directions well. Many facilities will require you to have cpr and first aid training as well.