It’s not common knowledge, but sunburn on the top of your head can have a negative effect on the volume of your hair. A sunburned scalp will cause hair to fall out, leading to thinner hair with reduced volume. So, if you’re going to be out in the sun for more than 20 or 30 minutes, plan to wear a hat or put some sunscreen on the top of your head. Burning the top of your head will also make the hairs themselves brittle and thin, which decreases the amount of volume in your hair. Many men wear a baseball cap, stocking cap, or cowboy hat on a day-to-day basis. Unfortunately, this can have a negative effect on the volume of your hair. Wearing a hat can compress your hair and reduce its volume, and can also reduce circulation to your scalp. This, in turn, will reduce the health and volume of your hair. Wearing a tight hat every day can also damage your follicles and cause your hair to thin. If part of the reason your hair has lost volume is that your hair is thinning, a hair-growth product may be the most effective way to restore hair volume. Talk to your doctor, and see what type of hair-growth product they recommend. It is important to note that these products both have better success rates at stopping hair loss than they do with re-growing lost hair, so be proactive and consult your doctor as soon as you notice your hair starting to thin. The two most popular hair growth products on the market contain minoxidil (found in products such as Rogaine) and finasteride (found in products like Propecia). Minoxidil is a topical treatment and finasteride comes in pill form.

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Write a summary of the previous text in Chinese:
避免头皮被晒伤。 不要每天戴太紧的帽子。 考虑使用生发产品。