Although freezing temperatures can kill head lice and nits, several days may be necessary depending on temperature and humidity; freezing is rarely (if ever) needed as a means for treating head lice.
Kill head lice by washing infested articles in hot water (at least 140°F) and drying in a hot dryer. Items that cannot be laundered such as headgear, earphones, and bike helmets, can be placed in a plastic bag and put in a freezer. If the freezer is 5°F or lower, all lice and eggs should be dead within 10 hours.
After each treatment, checking the hair and combing with a nit comb to remove nits and lice every 2–3 days may decrease the chance of self–reinfestation. Continue to check for 2–3 weeks to be sure all lice and nits are gone.
The peak season for lice infestation is August through October and again in January. Head lice are tiny parasitic insects that feed on human blood. Lice come in three forms: nits (eggs), nymphs (baby lice), and adults. Nits are white or yellowish-brown and about the size of a poppy seed.
While there is no “season” for head lice, it can be more common in the winter months as children and families are in tighter quarters, families gather for the holidays and winter apparel is swapped and shared.
In fact, adults can get lice anytime their hair is in close contact with the hair of someone who has lice. Whether public transportation, concerts, or crowded areas, any situation in which there is hair to hair contact puts adults at risk of getting lice.
Just like with mattresses, lice can only live on any bedding—whether it's sheets, pillows, or comforters—for 1-2 days. Without a human scalp as a source for food (blood) for longer than 1-2 days, lice cannot survive.
Ivermectin (Sklice).
This lotion kills most head lice, even just-hatched lice, with just one use. You don't need to comb out lice eggs (nits). Children ages 6 months and older can use this product.
New eggs are attached to the hair shaft very close to the scalp. Eggs that still contain a louse embryo are brownish in color, while the empty egg shells are white to grey.
Lice cannot “fall” on pillows, sheets, stuffed animals, and other bedding unless the hair that they are attached to fall. But they can't live on these surfaces, or on hats, scarves, furniture, or carpet. They also can't live on pets or any other animals. Nits can't live without a human host.
Typically, 10–15 head lice are found. The number of lice often depends on personal hygiene, for example, how often the person bathes, shampoos, or changes and washes his/her clothing.
Adult lice can't live longer than 24 hours or so on nonhuman surfaces like carpets, hardwood floors, clothing, furniture, sports helmets, headphones, or hair accessories. However, if you have identified lice in your home, isolate and wash those items and areas within at least 72 hours.
Lice can be hard to get rid of. If you still have lice 2 weeks after you started treatment, let your doctor know. Your doctor may want to try a different medication or repeat treatment in case any nits were left behind and hatched after treatment.
Lice and nits can't survive the high heat. It's true that lice and nits can't survive temperatures above 113°F (45°C). This makes them susceptible to any heat source, such as a hairdryer or the plates of a hair straightener.
There are recent studies that show that treatment of lice with heat can be quite effective in killing head lice. Products such as Lousebuster are very effective but even a home hairdryer can successfully treat lice.
Lice are also tenacious and can't be killed with a hot shower or strong shampoo. If you find evidence of lice treat all members of the household. Also, wash linens and towels on a hot setting of the washing machine.
To confirm a case of head lice, you need to find live lice. Children can have a few nits without actually having a case of head lice. Usually children have no more than 10 to 20 live lice.
Repeat treatment every day or every other day for 2 weeks. Some lice eggs (nits) survive head lice treatments. The only way to be sure that lice won't come back is to pick out all nits. Nits left on the hair can hatch and cause a new case of head lice.
Nits are often confused with other things found in the hair such as dandruff, hair spray droplets, and dirt particles. If no live nymphs or adult lice are seen, and the only nits found are more than ¼-inch from the scalp, the infestation is probably old and no longer active and does not need to be treated.
Adults are not immune to head lice. In fact, if you have any close contact with children or even parents of children you can be at risk of catching them if they have them. Lice transfer primarily through head to head contact, so you would have to get close to the other person.
Do not use a conditioner. It can keep the lice medicine from working. Rinse well with warm water and towel dry. Do not use the towel again until it has been laundered.
Small studies have also shown that tea tree oil in combination with lavender oil can kill lice eggs and reduce the number of live lice. Tea tree oil seems to be relatively safe for use on the skin, although it can cause irritation or swelling for some. Remember, though, that it is poisonous if swallowed.
Items that can't be washed in the washer can be dry–cleaned OR be placed in a sealed plastic bag for 2 weeks. Soak combs, brushes, hair barrettes/clips/ties in hot water (130°F) for 5-10 minutes. Vacuum the floor and furniture, where the person with lice sat or lay.
Vinegar contains properties that kill and get rid of nits and lice. This mixture should be applied directly to the whole scalp. Mix 1 cup of vinegar with 1 cup of warm water. Next, distribute this mixture onto the scalp and cover your hair with a hair cap.
If you see sesame-seed-shaped objects, those are the nits and lice, which can be brown or grey and stand out against the white paper towel. “The nits may look like they have tails that stick out the back,” says Faulkner.