There are numerous reasons why students with disabilities struggle in school. A key reason is professionals in the field may not pay enough attention to students' overwhelmed cognitive capacity. Cognitive load theory explains that all humans have limited capacity at any given time to use their auditory, visual, and tactile inputs (independently or collectively) to acquire new information and store it in long-term memory. When available cognition is overwhelmed -- which can be caused by any number of reasons -- learning cannot occur. In this article, we introduce the key aspects of cognitive load theory and give specific examples of how special educators can use this information to shape their instruction to support students' unique needs.