Frozen? Let it go to reset circadian rhythms.

The molecular events in response to severe hyperthermia are not fully understood, and research has focused mainly on the effects of cooling at temperatures between 28°C and 35°C. In a new study, Fischl et al have analysed human cardiomyocytes at lower temperatures (8°C, 18°C and 28°C) and identified a novel mechanism by which hypothermia synchronises the circadian clock: cooling induces nuclear accumulation of transcripts that encode negative regulators of the circadian clock, which are released into the cytoplasm upon rewarming allowing synthesis of specific clock proteins.