Question

why can't we measure human temperature using laboratory thermometer

Answer 1

Since the laboratory temperature changes its temperature sudden and soon . so we cannot measure human temperature using laboratory thermometer.

Answer 2

The laboratory thermometer is made up of alcohol. When you put the the thermometer in the material whose temperature you want to check, you can check it without lifting it as its length is long but when you take it out the alcohol will become the room temperature again.