Once Upon a Fever — Angharad Walker

From the critically acclaimed author of The Ash House, in a society where emotions themselves are thought to be the cause of the illness that has taken over the world, sisters Ani and Payton must unravel a dark truth in this story that explores the depth of our own strength in how we observe and deal with our emotions.
Since the world fell sick with fantastical illnesses, sisters Payton and Ani have grown up in King Jude's Hospital.

Payton wants to be a methic like her father, working on a cure for her mother's sleeping fever. Ani, however, thinks the remedy for all illness might be found in the green wilderness beyond the hospital walls.

When Ani stumbles upon an imprisoned boy who turns everything he touches to gold, her world is turned upside-down. The girls find themselves outside the hospital for the first time, a dark mystery unraveling...