You may have packed away your bikini several months ago, but hopefully you didn't stash your sunscreen in your medicine cabinet, waiting for the warm weather to return. Sunscreen is now a year-round necessity, and it may be time to take yours out of mothballs.

Unbeknownst to many people, in the early or late winter, you are still at risk from the sun's ultraviolet rays (UVR). Therefore, it's just as important to practice good sun protection during periods of extended outdoor exposure, especially when snow skiing or ice skating or even building a snowman on a cold, clear winter day. The fact is, snow strongly reflects UVR. If you generally head south for a winter break, your sunscreen should be packed in with all your vacation gear. The truth is, there is no vacation time from your sunscreen.

It is also important to use your sunscreen correctly and in the right amount for true effectiveness. Did you know that to achieve the SPF value listed on the sunscreen container you have to apply 2 mg of sunscreen per square centimeter of skin? This is actually a very large amount. Most people apply about 0.5 to 1.5 mg per square centimeter, and they also apply it unevenly, reducing their protection to between one-fifth and one-half of the SPF stated on the container. That means you think you're getting the full SPF 15 that's listed on the product, but in fact you're only getting an SPF of 3 to 7. So here's what you need to know:

Also, it's time to stop playing around with the concept of a "healthy" tan. Dermatologists have declared that tanning parlors and sunlamps are unsafe. The U.S. Department of Health and Human Services released a report in 2005 prepared by the National Toxicology Program (NTP). It says ultraviolet radiation from sunlamps and sun beds is "known to be a human carcinogen." So, why risk it?

Speak with a dermatologist about what SPF is right for your skin color and family or medical history. If you've had skin cancer, you may need a higher level of protection — a sunblock instead of a sunscreen. Wearing sun-protective clothing is also a good bet.

Now, if after all is said and done, you still don't feel complete without a sun-kissed look, investigate local day spas or salons that offer spray-on tans. Applied correctly, they look just like the real thing, and only you will be the wiser. And that's in more ways than one!

Dr. Harmon

"When you talk about treating acne scars, you have to look at three different categories," says Christopher B. Harmon, M.D., of the Total Skin and Beauty Dermatology Center in Birmingham, Ala.

Ice pick scars, characterized by their narrow, deep "ice pick" appearance, are typically less than 2 mm wide and extend into the subcutaneous layer. "Treatment for these are punch grafting or punch excision," Dr. Harmon says, "which is removing the scar by cutting it out and sewing the skin together."

Boxcar scars are broader — 3 mm to 5 mm wide — with a sharp shoulder and a vertical wall, Dr. Harmon explains.

"A classic chickenpox scar is a good example," he says. "Typically, they are treated with a much wider range of treatments."

One technique, punch elevation, involves cutting out the base of the scar and lifting the depressed area to the surface, Dr. Harmon says. Then, dermabrasion or laser techniques can be used to recontour the wall of the scar so that it doesn't cast as much of a shadow, he adds.

Atrophic or undulating scars show up when the patient is 40 or 50 years old. "The skin loses elasticity and becomes lax," he says, "and laxity contributes to the depressed areas."

Injecting a filler such as collagen, hyaluronic acid or transferred fat is the best treatment for this type of scar, he says, though fillers require follow-up to maintain the correction.

"You can also use lasers — ablative and nonablative," Dr. Harmon says. "Nonablative lasers have no downtime, unlike the CO₂ laser that has real long recovery."

He also says ablative laser treatments can potentially lighten the skin in some ways or cause hyperpigmentation.

Dr. Harmon says it's important to have realistic expectations.

"We are doing surgery to get rid of a scar without creating a new scar, and that, by definition, is difficult," he explains.

Even so, the improvements are noticeable, he says. "A good rule of thumb is a 30 percent to 50 percent improvement in acne scarring." And that kind of difference can have an immense impact on quality of life, Dr. Harmon says.

"Acne scars are very common and have a huge psychosocial impact. Treatment can be immensely rewarding for both the patient and treating physician."