Here's a link to an explanation of dewpoint from the U. of NC. It basically confirms what we all have known all along; that dewpoints above 70 deg. makes us feel unconfortable and that when above 80 deg., can be dangerous to human health.

Here is a link that might be useful: Cmse

And you know what you get when the dew point is higher than the temperature?
(guess and scroll down to see the answer)

Fog