Acute hypothermia is caused by A) rapid loss of body heat. Hypothermia is a condition of a medical emergency which can be happened if somebody loses heat faster than his/her ability to produce heat. This condition is might have happened if a person has a high temperature caused by a heavy activity and suddenly stop that activity. This situation will make the body temperature to drop down significantly.
i think it's the first one because doctors aren't the ones who get rid of the old needles. most of them time it's not even doctors who give you shots, it's nurses.