This week on Stuff Mom Never Told You, Cristen and I tried to warm you up, only to cool you right back down. Monday’s topic was kissing, something that’s guaranteed to give a person a fever, if Peggy Lee is to be believed. Most of the time, we’d prefer other people’s saliva stay far away from us, so why are we so eager to swap it with a person we love? Scientists aren’t quite sure if kissing is a learned behavior, or if we come wired to do it, but of course, there’s evidence that we’re learning valuable things about our partner when we press our lips together. I hope you’ll listen to this podcast, but my advice is not to share things you learn while you’re in the heat of the moment. Nothing kills a mood quite like informing your special someone that kissing might be modeled after mother birds chewing up food and then feeding it to their babies.

Our sources for this episode:

• “Put your sweet lips…” by Keith Thomas, the Sunday Times
• “Saliva: Secret Ingredient in the Best Kisses” by Robin Lloyd, LiveScience
• “The Science of the Smooch” by Tracy Clark-Flory, Salon
• “The Kiss of Life” by Joshua Foer, New York Times
• “The Kiss: A 50th Anniversary Lecture” by Leonore Tiefer, The Kinsey Institute
• “Kisstory tells the history of kissing,” Hindustan Times
• “Things You Didn’t Know About Kissing” by Sheril Kirshenbaum, Discover (available via library database)
• “Kissing right way begins in the womb” by Andy Coghlan, New Scientist
• “62 Years Later, a Kiss That Can’t Be Forgotten” by Sewell Chan, New York Times
• “The 10 Most Important Kisses in the Universe” by Maggie Koerth-Baker, Mental Floss

Feeling your temperature rise with all this kissing talk? Well, if you’re a woman, that warmth might be a welcome change. On Wednesday, we talked about why it is that women always seem to feel colder than men do. As someone who’s shivered my way through a work day while male coworkers walk around in t-shirts, I was especially interested to hear what science would have to say about this phenomenon. There are many factors involved, including weight, diet, age and stress level, but I thought it was pretty cool that women’s bodies may work especially hard to keep the core body warm at the expense of our limbs. The saying “cold hands, warm heart” turns out to be true, and we have to agree it has a nicer ring to it than “cold hands, warm kidneys.”

Want to learn more? Have a look at our source material:

• “Warm Heart, Cold Hands” by Amanda Schaffer, Slate
• “Why do women always feel colder than men?” by Kate Wighton, The Times
• “Why are women always cold?” by Cecil Adams, The Straight Dope
• “An (alleged) extra layer of female fat” by April Holladay, USA Today
• “Why You’re Always Cold (or Hot) at Work” by Laura Morsch, CareerBuilder
• “When the Office Gives You Chills” by Phyllis Korkki, New York Times
• “One Shivers, the Other Doesn’t” by Kate Stone Lombardi, New York Times
• Raynaud’s Association Web site
• “When Cold Fingers Mean Raynaud’s, or Worse” by Winnie Yu, New York Times
• “Getting to the Root of Raynaud’s” by Winnie Yu, New York Times

Want to talk about kissing and how cold it is in your office? Then why don’t you head over to the Stuff Mom Never Told You Facebook and Twitter pages and start a conversation? And if you’re on the go, I highly recommend the HowStuffWorks.com iPhone app.