A fever results when the immune system, apparently in response to an invasion of bacteria or viruses, produces substances in the blood called pyrogens. This causes the hypothalamus to “reset ” to a higher level.
जंतू किंवा विषाणूंचे आक्रमण होऊन रोगप्रतिकारकक्षमता रक्‍तामध्ये तापजनक पदार्थ तयार करते तेव्हा ताप येतो.