Your skin is also what we call a microbiome; it's teeming with microorganisms, most of which are invisible to the naked eye. Even when you think you're clean (like right after a long, hot shower), you still have bacteria, fungus, yeast, and parasites living on and in your skin (gross, but true). They're supposed to be there, of course, and normally they all live in harmony, but when that delicate balance gets disturbed (by hormone fl uctuations or changes in your diet, for example), one component overgrows, and your skin reacts. Rosacea, acne, and many rashes are caused, at least in part, by bacterial overgrowth or imbalance.
Hey, Dr. Wu
Q: So, how many skin-care products do I really need?
A: Two to three products— tops—should do the trick: a cleanser, sunscreen (typically in the form of a moisturizer with SPF), and a treatment of some kind in the evening, depending on your particular needs.
Over the years I've come to realize that skin care basics often confuse people the most. In fact, the majority of questions I receive from my online newsletter are about the simple stuff, such as the proper way to wash one's face or what to look for in a moisturizer. That's why I'll be sharing tips and tricks, as well as specifi c product recommendations, along the way.
Is It Hot in Here? Your Skin Controls Your Core Temperature
The skin maintains your core temperature of 98.6°F by controlling the amount of water that evaporates from your body. The evaporation of water from the skin is what cools you down. If it's very cold outside, you won't sweat as much because your body is conserving heat. On the flip side, if it's really warm outside, your body increases perspiration (obviously); as the water evaporates from your skin, you cool off. That's why people who live in dry heat don't feel as uncomfortable as people who live in more humid parts of the country. It could be 110 degrees outside, but if you're in, say, Arizona, the sweat on your skin will evaporate quickly because the air is dry. On the other hand, if you're in south Florida, it might be only 85 degrees, but there's already so much water in the air that the sweat evaporates much more slowly. It's like being in a steam shower— sticky and uncomfortable.
Were you to lose large areas of your skin— in a fire, for example— you'd also lose your ability to regulate your internal temperature. That's why burn victims have to be wrapped from head to toe and kept in warm beds. There's a huge risk of developing hypothermia when you can't prevent water loss or hold in heat. That is also why a serious sunburn (as in second degree or worse, when the skin blisters and peels off) can make you shiver and shake.
Skin Enemy #1: Inflammation