Dear Paula,

Summer is here and in my area, with summer comes sweat, and a lot of it. Sweating is the source of two problems I struggle with. My most pressing sweat-related problem is my hair.  I jog most days and I end up with hair that is quite damp with sweat.  I don't like to shampoo daily but I hate having a sweaty head.  I use some baby powder when it gets really greasy, but I still feel a bit gross.  Is it worthwhile, and non-damaging, to simply rinse my hair after a workout (and mostly skip the dryer)? Some people advocate rinsing followed by conditioning. That seems like too much for me to deal with.

My second question is about sunscreen. I wear sunscreen everyday. In summer it's extremely difficult because it seems that as soon as I put it on, I'm sweating it off. Often, I'm sweating lightly even as I try to apply it! Do you have any suggestions? I would really appreciate some guidance on these issues as I greatly respect your advice.

April, via email

Dear April,

Your first question is simple to answer, even though you may not agree with the response: you need to shampoo after your workout in order to remove the sweat residue and smell from your scalp and hair. Rinsing with water will help but because oil and the salt residue from sweat produced by the hair follicle on the head needs more than just water to remove, ideally a gentle shampoo should be used. Plus, if you’re going to shower anyway, you may as well shampoo. This is the surefire way to avoid that “gross” feeling knowing your hair was recently soaked with sweat. To get a bit technical: The hair follicles on a person’s scalp are connected to apocrine sweat glands. Unlike eccrine sweat glands on other parts of the body (think legs and arms—not underarms) whose sweat is composed primarily of water and salt, apocrine sweat glands produce a fatty oil that can interact with bacteria on our skin, producing a foul-smelling odor. When we perceive a person as having body odor, it is usually because of aporcrine sweat glands. Water alone cannot cut through the oily portion of apocrine sweat glands, but the surfactants—detergent cleansing agents in shampoo—can do the work perfectly. After you shampoo, a bit of conditioner can prevent tangles and make combing far easier.

Dealing with summer heat and trying to apply sunscreen evenly and keep it on for as long as possible is definitely a challenge! Being able to control your home environment with air conditioning or a strategically-placed fan can go a long way toward improving your comfort, not to mention keeping perspiration to a minimum. If your home does not have air conditioning, place an oscillating fan in your bathroom (or wherever you wish to apply sunscreen) to keep things cool. You can also try pressing a towel-wrapped cold pack to your face for a moment or two before applying sunscreen. This will cause a slight drop in skin temperature, perhaps enough to allow you to apply your sunscreen evenly before you start sweating again. Beyond these tips, the only thing you can do is use sunscreens that are labeled as water-resistant and are silicone-based. The silicone base of many spray-on sunscreens clings well to skin and is typically more resistant to sweat than water-based sunscreen creams and lotions. Kinesys offers an excellent range of spray-on sunscreens. You can also find good options from Coppertone and Paula’s Choice. Be sure to reapply any sunscreen if you continue to perspire heavily during hot summer months and will be exposed to sunlight (if you’re hiding out inside to escape the heat, the sunscreen does not need to be reapplied at regular intervals).