Searching casually, the answer to “Is a body temperature of 37.5°C normal?” comes from the chief physician of a provincial top-tier hospital in 2024: an axillary temperature of 37.5°C is considered a fever. I clearly remember in 1998, when I caught a cold and had a high fever of 40 degrees Celsius; moving my head only made me feel a slight wobble like tofu in my head. At that time, the normal body temperature for humans was 37.5°C. During the pandemic, the standard body temperature has changed to 36.5-37.2 degrees. In reality, most people’s “normal” body temperature was around 36.5 degrees. When measuring during a low fever, it is generally 37.5°C. There was a previous article discussing the relationship between human body temperature, immunity, and viruses, using bats that carry numerous viruses as an example. The average human body temperature has decreased by at least 1°C compared to before. This trend is closely related to the properties of chemical medications; who can escape from chemical drugs when they fall ill? Even if you never get sick, everything you consume daily—chicken, fish, meat, eggs, milk, vegetables, fruits—contains various chemical substances indirectly. Packaged foods and beverages on the market are even worse; it doesn’t matter how expensive they are. Commercial interests and human nature have long determined that they cannot be safe. Nowadays, every household’s drinking water has been replaced by tap water instead of groundwater. Why? Apart from the need for equipment in some commercial housing, the main reason is that groundwater has been polluted, with factories discharging waste. Many people have seen examples of this in their daily lives. Regarding sleep, before the era of electronic devices, people would feel extremely sleepy by 8 or 9 PM and go to bed early. They would wake up around 6 or 7 AM. Outdoor activities were much more frequent than now. In every aspect, the average human body temperature has decreased, and immunity has declined, making it easier to get sick than before. Regardless of personal wealth or the skill of doctors, no one can withstand the “slow medicine” of the environment.