There is no specific time limit for how long a fever can be treated with an IV, but it depends on the cause of the fever, the effectiveness of the treatment, the presence of complications and other factors. For example, for patients with a simple viral cold who have a fever, there is no need for IV treatment at this time, and most patients can get better and resume normal body temperature after 2-3 days by taking oral medication and drinking more water. For patients with fever caused by lower respiratory tract infections, such as pneumonia caused by bacterial infections, the body temperature can gradually decrease in 3-5 days through effective antibiotic anti-infection treatment, and the effect can be seen. However, in patients with severe infections, such as combined sepsis and lung abscess, the duration of fever is usually significantly longer, and even with strong antibiotic anti-infection treatment, some patients can see the effect only after 5-7 days or even longer. Therefore, it is necessary to clarify the cause of the fever and then target it with effective drug treatment, avoiding blind drip treatment, which is ineffective.