How small a change in temperature can a person detect by touch? How could smaller changes in temperature be detected?
The change in temperature that can be detected by a person is dependent on many factors. Some of these are the location on the body where the temperature change is being perceived, the temperature range in which the change is being perceived and whether the temperature is increasing or decreasing.
Research has shown that at a small area located at the base of the thumb people are able to perceive temperature changes of 0.02 to 0.07 degrees Celsius. This is the threshold of detecting a change in temperature.
An increase in temperature of the same magnitude as a decrease is less likely to be detected by touch. Areas of the skin covered by hair have a considerably lower ability to sense temperature change. People are also more likely to notice a change in temperature if a visual cue of the same is provided. Prolonged exposure to temperatures in a particular range decreases the ability to notice changes in temperature in that range; there is a higher sensitivity for temperature change that is significantly different.