<Table> <Tr> <Td> </Td> <Td> This section needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (October 2016) (Learn how and when to remove this template message) </Td> </Tr> </Table> <Tr> <Td> </Td> <Td> This section needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (October 2016) (Learn how and when to remove this template message) </Td> </Tr> <P> When the air temperature is high, the human body uses the evaporation of sweat to cool down, with the cooling effect directly related to how fast the perspiration evaporates . The rate at which perspiration can evaporate depends on how much moisture is in the air and how much moisture the air can hold . If the air is already saturated with moisture, perspiration will not evaporate . The body's thermoregulation will produce perspiration in an effort to keep the body at its normal temperature even when the rate it is producing sweat exceeds the evaporation rate, so one can become coated with sweat on humid days even without generating additional body heat (such as by exercising). </P> <P> As the air surrounding one's body is warmed by body heat, it will rise and be replaced with other air . If air is moved away from one's body with a natural breeze or a fan, sweat will evaporate faster, making perspiration more effective at cooling the body . The more unevaporated perspiration, the greater the discomfort . </P>

What's the difference between humidity and dew point