Environmental variability is common in most aquatic environments, yet it has been largely stabilized in laboratory experimental physiology aimed at understanding physiological responses to environmental challenges. Climate change is expected to increase climate variability and exacerbate environmental extremes, yet we know less about the impacts of this variability on fish physiology. This information will be crucial in gauging species' vulnerability to climate change. Incorporating variability into experimental designs is challenging and leads to difficulties in interpreting data within experiments and across multiple experiments where the experimental designs can be different. In this presentation I will discuss how we have been incorporating variability into our experiments to closely match natural environments, the lessons we have learned with respect to sampling times/durations in thermally variable experiments, and the types of physiological data that we collect that can be applied to real-world scenarios. I will use examples from our published research on the physiology of wild Atlantic salmon from thermally distinct rivers in Atlantic Canada and discuss a new and on-going experimental design in our lab that focuses on incorporating both daily and seasonal environmental variability into physiological experiments in salmonids from eggs to adults.