Early Riser

Imagine a world where all humans must hibernate through a brutally cold winter, their bodies dangerously close to death as they enter an ultra-low metabolic state of utterly dreamless sleep. All humans, that is, apart from the Sleep Marshalls, a group of officers who diligently watch over the vulnerable sleeping citizens.
John Fugue is a junior Sleep Marshall who hears of a conspiracy - a viral dream is somehow spreading amongst those in the hibernational state, causing paranoia, hallucination and a psychotic episode that can end in murder. When the Marshall, John Fugue, enters the Sleepstate himself and wakes two months later, all those who knew about the dream have disappeared . . .

Jasper Fforde