Final answer:
Body mass index (BMI) is not considered one of the vital signs; vital signs include temperature, pulse, respiration, and blood pressure.
Step-by-step explanation:
The vital signs commonly measured to assess a person's health include temperature, pulse, respiration, and blood pressure. These signs are objective, measurable, and can reflect the body's basic functions. Among the options provided, Body mass index (BMI) is NOT considered one of the vital signs. BMI is a measure of body fat based on height and weight that applies to adult men and women. It is used as a screening tool to identify possible weight problems, but it is not used to monitor immediate physiological functions like the vital signs.