I keep encountering idiots who claim some particular dew point temperature is always comfortable. This is so absurd that anyone who says it has absolutely no understanding of the word comfortable or what dew point is.
Dew point is literally the temperature at which dew will form if the current air mass is cooled to that temperature. It also corresponds to 100% RH. This of course means that if the dew point is 10°C (50°F) and the temperature is 10°C (50°F) then the %RH is 100% and water is condensing out of the air and dripping down everything that’s at or below the air temperature.
So if you ever encounter somebody who claims that some dew point temperature is always comfortable ask them, Do you really think that dripping wet 100%RH is comfortable.
If you want to judge comfort go for relative humidity where above 80% feels yucky damp and below 30% feels horribly dry (cracked skin and static electricity problems)
Paul Hutchinson's Blog 