The main reason for choosing a cold light source for the shadowless lamp in the operating room is that there are times when the light source needs to be especially close to the patient's wound. The patient's epidermis has often been cut in surgery, the internal structure of the body will be very strong heat induction, the doctor because of the gloves, and the protection of normal human epidermis, the feeling is very different from the patient.
At the same time, if the hot light source is easy to accelerate the evaporation of water from the patient's wound.
So cold light sources are often used for illumination during surgery.