Diagnostic errors are considered a blind spot of health care delivery and occur in up to 15% of patient cases. Cognitive failures are a leading cause of diagnostic error and often occur as a result of overreliance on system 1 thinking. This narrative review describes why diagnostic errors occur by shedding additional light on systems 1 and 2 forms of thinking, reviews literature on debiasing strategies in medicine, and provides a framework for teaching critical thinking in the intensive care unit as a strategy to promote learner development and minimize cognitive failures.