Collection and analysis of physiological reading can predict when a person is likely to develop a fever before that person's body temperature increases. In an implementation a device such as a wearable band collects physiological information from its wearer. The physiological information may include heart rate or respiration rate. The person's physiological information classified by an algorithm derived through machine learning techniques. The algorithm may be trained by using data from other individuals who are both healthy and who are sick and/or trained from past reading of the person's own physiological readings. The algorithm may evaluate a value of the person's physiological information to generate probabilities that the person is healthy or that the person likely to become sick and/or develop a fever in the next few days.
