It was a swampy and hot 90+ degree day in New York City, the kind that makes steam drift up from the black asphalt streets and your hair fall flat and frizzy after sopping up the gummy humidity.

And I was beginning to wonder if Avon realized what they had gotten themselves into.

I was invited to try a blowout with the brand's new Lotus Shield Anti-Frizz Treatment at the last stop of Avon and Cosmopolitan magazine's Frizz-Free Revolution Tour, which had visited Houston, Miami, Atlanta and Philadelphia in a glass-enclosed "salon on wheels" to bring sleek strands to the masses.

Global stylist advisor Tippi Shorter -- who has glamourized the locks of Rhianna and Beyoncé and had just flown back from doing Alicia Keys' wedding hair in Corsica -- was on hand to talk frizz.

"The more damaged your hair, the more chance it has of swelling in humidity," Shorter told me. "Fighting frizz successfully is all about creating your own cocktail of products, and starting the process while you're washing your hair in the shower."

Shorter says the Lotus Shield serum essentially acts like a weightless leave-in conditioner that should be applied to wet hair. After three to four uses, Avon claims your blowouts will hold up to humidity as high as 97%, as well as last at least a day longer than usual after three to four consecutive uses.

Inspired by the natural protective shield of the lotus leaf, the product doesn't actually contain lotus. Instead, it harnesses a water-resistant technology that causes moisture to pool like droplets against the surface of hair instead of absorbing and saturating the strand.

After squeezing a dollop of the product into my hands, I gently finger-tapped to feel the consistency and was surprised as the clear serum whisked away to sleek-feeling nothingness. There was no sticky or tacky after-feel left in its wake either.

And most amazingly, a blowout followed by flat ironing to seal in the product on one of the muggiest days of the summer (and in an open-air mobile salon to boot) left me with touchably soft and frizz-free locks that are still resisting the humidity two days later as I write this.

I would offer to share the love, but you're going to have to get your own bottle -- otherwise you'll need some serious claws to get this little gem out of my beauty bag now.

See the top hair and beauty trends for Fall 2010.