Observing fever and Not taking medicine?
Kucchivikara-vatthu includes,

A sick person endowed with five qualities is hard to tend to: he does what is not amenable to his cure; he does not know the proper amount in things amenable to his cure; he does not take his medicine; he does not tell his symptoms, as they actually are present, to the nurse desiring his welfare, saying that they are worse when they are worse, improving when they are improving, or remaining the same when they are remaining the same; and he is not the type who can endure bodily feelings that are painful, fierce, sharp, wracking, repellent, disagreeable, life-threatening. A sick person endowed with these five qualities is hard to tend to.
A sick person endowed with five qualities is easy to tend to: he does what is amenable to his cure; he knows the proper amount in things amenable to his cure; he takes his medicine; he tells his symptoms, as they actually are present, to the nurse desiring his welfare, saying that they are worse when they are worse, improving when they are improving, or remaining the same when they are remaining the same; and he is the type who can endure bodily feelings that are painful, fierce, sharp, wracking, repellent, disagreeable, life-threatening. A sick person endowed with these five qualities is easy to tend to.
A nurse endowed with five qualities is not fit to tend to the sick: He is not competent at mixing medicine; he does not know what is amenable or unamenable to the patient's cure, bringing to the patient things that are unamenable and taking away things that are amenable; etc.