Although sweat is often linked with uncleanliness and leaves many of us left feeling embarrassed when it appears but according to scientists, a bit of sweat may not be a bad thing - especially if you are single this Valentine's Day. "Pheromones are what we call here in Germany Sexuallockstoffe, which work on men and on women alike," the Daily Mail quoted Gabriele Frobose, who co-authored theu00a0Royal Society of Chemistry book Lust and Love, Is it More Than Chemistry - with her husband, as saying. "Those pheromones are included in the sweat. This is why some girls like to wear the T-shirts of their boyfriend and vice versa. When I was young my boyfriend and I changed T-shirts without thinking about what we were doing. I discovered recently that my 19-year-old son is now doing this with his girlfriend."

"This is obviously because there is still some smell of your partner left in the clothes which you like." According to the book, an example of the appeal of sweat to lovers was highlighted by Napoleon Bonaparte. He once wrote to his wife Josephine, while he was campaigning, and said: "Please don't wash, will arrive in three days."