Off the host, adult head lice can live about two to four days at 74 degrees Fahrenheit (F) and one to two days at 86 degrees.
Washing, soaking, or drying items at a temperature greater than 130°F can kill both head lice and nits. Dry cleaning also kills head lice and nits. Only items that have been in contact with the head of the infested person in the 48 hours before treatment should be considered for cleaning.
Lice can survive in any weather temperature as long as the body temperature of their host is around 98.6 degrees. If a louse detaches from the host, it can live around 24 to 48 hours before they die.
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.
Lice are wingless insects that spend their entire lives on the human scalp and feeding exclusively on human blood. As long as their host is a warm 98.6 degrees and providing a comfortable, safe environment for them to live lice are not affected by the temperature outside.
Permethrin lotion 1% is approved by the FDA for the treatment of head lice. Permethrin is safe and effective when used as directed. Permethrin kills live lice but not unhatched eggs.
Because the active ingredients have remained the same all these years, new generations of head lice have become immune to them. Once lice become immune, the product no longer works. Scientists call this resistance.
The proportion of lice killed varied from 10% with the bonnet‐style hair dryer to 80% with the Louse‐Buster with hand piece.
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.
Petroleum jelly (Vaseline).
Like olive oil, many moms swear by this (other options: styling gel or mayonnaise). The thick jelly supposedly suffocates lice by clogging their breathing holes. For best results, coat the hair and scalp, cover it overnight with a shower cap, and wash out the next morning.
Either washing done with a water temperature of at least 50 degrees C or drying is necessary to kill head lice and nits.
Adult lice can live up to 30 days on a person's head. To live, adult lice need to feed on blood several times daily. Without blood meals, the louse will die within 1 to 2 days off the host.
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.
Head lice sometimes go away on their own because there are not enough insects to maintain the infestation, or they may persist for an indefinite period without treatment. With proper treatment, the infestation usually goes away within about two weeks.
After Treating with Lice Medicine
Use the nit comb to remove dead lice and nits. If some are still present but moving slowly, do not shampoo again. If lice are still active and no dead lice are found, call your health care provider. These lice may be resistant to the medicine.
DECONTAMINATION OF PERSONAL ARTICLES AND ENVIRONMENT: Since heat kills lice and their eggs, many personal articles can be disinfected by machine washing in HOT water and/or drying using the HOT cycle of the dryer. Eggs are killed in 5 minutes at 125 degrees F and adult lice die in slightly lower temperatures.
Vacuuming: While a vacuum is a good tool for cleaning up the ground after manual lice removal with a comb, it is not a wise idea to attempt to vacuum lice out of someone's hair. This is an uncomfortable and ineffective solution as lice have special claws to hold onto hair.
As previously discussed, hair color may kill the bugs, but with a full-blown infestation, can lice survive hair dye? Yes, they can. You may be successful at getting rid of some of the bugs with hair dye, or you may even use hair dye to get rid of all of them.
While the ovicidal (egg-killing) property is not as good, with tea tree oil taking 5 days to cause a 50% kill rate, louse eggs hatch in 5-8 days, so prolonged use of tea tree oil over the course of 2 weeks could be an effective eradication measure.
Coconut, tea tree oil, lavender, eucalyptus, rosemary, lemon grass, and peppermint are scents popularly believed to repel lice. Using any coconut scented shampoo and conditioner is an easy way to increase your defense.
The only way to prevent them from hatching would be to remove them with a good metal nit comb, or your fingernails. Nits are laid by the mother and attached with a glue she formulates, to sit on the hair shaft in the perfect spot to incubate and hatch.
Adult head lice can survive for 2 days and nits for around 1 week on a hairbrush. Soaking combs or hairbrushes in hot water of at least 130°F (54.4°C) for 5–10 minutes will kill any lice and nits.
Head lice should not be considered as a medical or public health hazard. Head lice are not known to spread disease. Head lice can be an annoyance because their presence may cause itching and loss of sleep.