Mothers' intuitive models concerning the causes of fever in their children and their beliefs about the effects of different treatments were compared to modern, folk and ancient models of the subject. A questionnaire was devised, presenting statements that were generated from the responses in a preliminary study, and from ancient, folk and modern views about fever. This questionnaire was answered by 147 mothers whose youngest child was up to eight years old. The sample consisted of four groups, who differed in their educational background: less than 10 years, 10-12 years and more than 12 years of schooling, and a group of professional nurses. Results reveal a complex picture. Unlike in physics, naive understanding does not duplicate ancient models. With increasing education, the views held by the ancient and contemporary folk beliefs are rejected. Many results of modern science are known throughout the population, and this is true both for practical recommendations and for their rationale. Even so, the medical model is only partly accepted, and is assimilated in a somewhat distorted form.