Diapause is considered an important adaptation for survival of adverse winter conditions; however, insects often enter diapause long before the onset of winter. Thus, diapausing insects must also be able to survive these warm conditions which can be quite metabolically taxing despite relative inactivity. We sought to test the consequences of the pre-winter warm conditions of varying temperatures and lengths on diapausing pupae of Pieris napi. After raising pupae into diapause, we placed them at one of three temperatures (15, 20, 25 °C) for anywhere from 1 to 16 weeks, followed by the same duration of winter conditions for all individuals. We measured weight at multiple points during the experiment and whether individuals survived the entire period to emerge as healthy adults. For a subset of individuals, we also made repeated metabolic measurements. Initial results suggest that pre-winter temperature had a substantial effect on the rate of pre-winter weight loss, while only the duration of the pre-winter period clearly affected survival. Upcoming analysis of the post-winter mass and survival insight into the longer-term impacts of pre-winter conditions on life history. The ability to tolerate extended warm periods during diapause is particularly important for understanding selection on voltinism, particularly as climate change makes these pre-diapause warm conditions longer and more intense.