There are many ways that teachers can address children with disabilities as well as the classroom.
One option is for schools to have a special class for children with disabilities. In this way, complete attention can be given to these children without the teacher having concerns in a mixed class.
If there is a mixed class, then the best support that a teacher can receive is the support of the principal, teachers, and parents. If all of these people are on board, the stress will be greatly diminished.
As for themes in the classroom, the teacher could speak about topics such as including people, diversity, and different methods of learning and teaching. By addressing these themes, the children in the classroom will be more understanding.