Nowadays, most people deal with fever by all means, and when they take out the thermometer and see that it is in the normal range, their nervousness will immediately relax and they will breathe a long sigh of relief and feel a lot more secure. Even if the patient is sweating profusely and nearly deflated, it does not matter. In fact, this is the time to breathe a sigh of relief also bacteria or viruses. When they are losing in the heat, they suddenly find that the white blood cells stop attacking and the surrounding area becomes cooler, which gives the bacteria or virus a chance to breathe. This inevitably prolongs the course of the disease, complicates it, and even results in sepsis, which can be life-threatening. Just one survey showed that the application of antipyretic agents prolongs the course of cold and flu by an average of 2-4 days. When a cold-blooded lizard is infected, it will not actively develop a fever, but it will choose a warm place to raise its body temperature by about 2°C. If the weather is bad, or if a warm place cannot be found in time, the lizard will most likely die. A young rabbit cannot yet generate its own heat, so if it becomes ill, it will also find a warm place to raise its body temperature; an adult rabbit that can regulate its own body temperature and make itself hot will also most likely die once it is blocked by antipyretics. The body will initiate a fever mechanism after infection, a resetting of the thermoregulatory center, all for a purpose and not out of control. This defensive adaptation to infection has existed throughout the animal kingdom for billions of years. There is absolutely no need for us to get upset about it. At the beginning of the last century, syphilis was very prevalent, but there were no effective drugs to treat it, so someone thought of using fever caused by malaria to treat syphilis, because malaria can be cured by herbal medicine. Someone then intentionally infected thousands of syphilis patients with malaria. At that time, the natural remission rate of syphilis was less than one percent, and this fever treatment achieved a thirty percent remission rate. In those days, more people recognized the value of fever than they do now. But it was not always encouraged to take a febrile approach to the disease. If a body temperature of 40°C can prevent infection, then we are better off keeping that temperature all the time, so why wait until after infection to fever? This is because a 40°C temperature has a significant cost in terms of increased energy expenditure, the potential for delirium, and perhaps central nervous system damage. It is in this constant weighing of the pros and cons that our bodies have evolved to this point. How could we be any different? If you had an appointment today and you were running a fever, you might prefer to extend your illness by a few days and take fever-reducing medication rather than lose that appointment. Generally for fevers below 40 degrees, there is no rush to relieve the fever. However, it is important to replenish sufficient water, nutrition and vitamins, and to take sufficient rest and keep warm to facilitate the establishment of resistance; after the fever or even high fever lasts for 4-5 hours, if you do not see any reduction, then consider applying antipyretic drugs, which usually work with a very small amount of medicine and are not easy to repeat again. Every cold and fever is a strengthening exercise for the body’s resistance, especially for children before the age of five, who have a low immunity and need to be perfected. And the stimulation of fever is the best way to do it. For patients with high fever greater than 40 degrees, especially those with combined heart disease, because of the possibility of inducing heart failure, early heat treatment should be performed. Also pregnant women, who are at risk of causing fetal malformation in early pregnancy and further aggravating the whole body in late pregnancy, should also have early fever reduction.