The World Economic Forum identified complex problem solving, critical thinking skills that facilitate it and creativity as the top skills needed in 2020 and beyond. [1] Critical thinking broadly consists of three components, i.e. information, processing (thinking) skills and the habit of using the processed information to direct behaviour. [2] In the health professions, the ability to gather information and evaluate associated assumptions and evidence to guide courses of action are key to preventing and solving problems. [3] Numerous studies reported that high-fidelity simulations are useful to improve critical thinking, decision-making, confidence, all-round communication skills and readiness for practice, [4][5][6] and in medical and nursing education, it is extensively used to link classroom teaching to clinical practice. [7][8][9][10] The essence of simulation-based education in healthcare is to expose students to real-life situations without the risk of harming patients, while they pursue specific learning outcomes. [11,12] The innate authentic nature of highfidelity simulations can however profoundly increase students' cognitive load, which may affect their learning experience and clinical performance. The incorporation of cognitive load theory (CLT) to facilitate the development of simulations that consider the cognitive interplay between working memory and long-term memory to optimise learning, [13] is therefore indicated. CLT is based on the principle that a person's working memory -the part concerned with learning and problem solving -has a limited capacity when dealing with novel information. However, when the working memory can access appropriate information stored in the long-term memory, its capacity seems to be limitless. [14] Students' total working memory load or cognitive load consists of the sum of the intrinsic cognitive load and the extraneous cognitive load. Intrinsic load (IL) refers to the inherent difficulty of the information or simulation, while extraneous load (EL) mostly refers to suboptimal instructional design factors that do not enhance learning. [15] Should either one or both components exceed working memory capacity, learning will be impaired. In developing simulation scenarios, educators should therefore consider the inherent difficulty of the scenario and increase students' working memory capacity accordingly by way of populating their long-term memories with the necessary information prior to the simulation. [15] Several interacting scenario elements that need to be considered simultaneously during the simulation, should preferably not be based on skills not yet mastered, [15] and a simulation requiring e.g. clinical reasoning, decision-making and complex communication, should be written around radiographic procedures that students can competently perform without much thinking. It is, however, also true that a slightly excessive cognitive load often results in associated increased learning, [14] and educators' challenge is to find the balance between an increased cognitive loa...