Laboratory learning forms a significant and integral part of engineering education, wherein students develop technical, collaborative, enquiry, and observation skills that go beyond theoretical studies. Engineering is inherently a practice-based profession, and consequently, laboratory work has been inseparable for engineering curricula. However, there is evidence suggesting that students encounter cognitive or information overload during modern laboratory classes, leading to reduced likelihoods of effectively achieving intended learning outcomes, as specified by the cognitive load theory. This article investigates how pre-lab online learning resources can be utilised to effectively manage cognitive load of engineering students, in the context of thermodynamics education. Qualitative and quantitative data have been collected from students as well as teaching staff on a range of parameters such as student preparedness, confidence levels, degree of engagement, and understanding. The findings of the study indicate that efficient student preparedness through pre-lab online resources can be utilised to effectively manage cognitive load of engineering students, leading to increased levels of understanding, preparedness, and confidence. It can be observed that there are influences from factors such as the quality of pre-lab resources and degree of engagement.