Answer:
Because it is the standard operational range for measuring the body temperature of a living individual.
Step-by-step explanation:
When making a measuring equipment like a thermometer, you attempt to keep the reading range (Span) as small as possible so that the reading is as accurate as feasible. Because sensors are often rated in percent of span (in this example, span = 45 C–32 C = 13 degrees Celsius), One percent of 13 equals 0.13 degrees Celsius, thus if your sensor has a usual accuracy of 1%, your temperature reading is accurate to roughly 0.1 degrees Celsius.
Your precision would be 0.2 degrees Celsius if you doubled the span. The reading accuracy is now becoming unsatisfactory. Readability is another advantage of analog and mercury clinical thermometers. The markings for 0.1 deg C would be ten times closer together if a mercury thermometer had ten times the range (span). There is a limit to the device's readability.