Multiple stressors, such as warming and invasions, often occur together and have nonadditive effects. Most studies to date assume that stressors operate in perfect synchrony, but this will rarely be the case in reality. Stressor sequence and overlap will have implications for ecological memory – the ability of past stressors to influence future responses. Moreover, stressors are usually defined in an anthropocentric context: what we consider a short-term stressor, such as a flood, will span multiple generations of microbes. We argue that to predict responses to multiple stressors from individuals to the whole ecosystem, it is necessary to consider metabolic rates, which determine the timescales at which individuals operate and therefore, ultimately, the ecological memory at different levels of ecological organization. Multiple anthropogenic stressors rarely overlap in perfect synchrony in time, yet most research quantifying how they interact assumes that they do.Stressor sequence and the degree of temporal overlap will have implications for ecological memory – the influence of past stressors on future ecological responses – from genes to ecosystems.Adding to this complexity, organisms with different generation times will experience multiple stressors (and the degree to which they overlap in time) in different ways.We propose that lifespan and associated metabolic rates can be used to define stressor type (continuous or discrete) and temporal overlap for different focal organisms.Moving forward, we need to embrace the temporal complexity of multiple stressors and quantify how various realistic asynchronous scenarios will alter their cumulative impacts across different ecosystems.