At what temperature do lice die and are they afraid of frost?

Lice, like most parasites that have adapted to live next to humans, are able to survive in very narrow temperature ranges. This is explained by the fact that insects simply do not need to develop in themselves resistance to heat or cold.

The temperature of a human home, as a rule, does not fall below zero, and people are unlikely to admit forty degrees on a room thermometer. This feature of parasites can be used to combat them.

So, at what temperature do lice die? Let's thoroughly understand this issue.

The effect of temperature on the activity of lice

At what temperature do lice die? Critical for these parasites is the mark on the thermometer above +40 ⁰C and below -5 ⁰C, however, this interval can significantly decrease or increase with the change of some environmental conditions. To a large extent, it depends on the stage of development of the parasite.

The effect of heat on lice

Lice tolerate very high temperatures. First of all, heat affects their ability to reproduce. At +40 ⁰C in the body of the female the process of egg maturation is suspended. A further increase in temperature leads to a delay in the development of the embryo in already deposited nits, but its death occurs only at +60 ⁰FROM.

The relatively high resistance of nits to high temperatures is explained by the presence of a dense protective shell that protects the embryo in the period most vulnerable to it. Adult insects do not have such protection. Their soft chitinous coatings are not able to protect them from the effects of heat and lice die at a temperature slightly above 55 ⁰C for 2-3 minutes.

Humidity can significantly affect the survival of lice. The high water vapor content in the air leads to a decrease in evaporation from the surface of the body of the insect. This, in turn, reduces heat transfer and causes overheating.

The following temperature patterns in the activity of lice were revealed at a relative humidity of about 70%:

• 40 – 45 ⁰C - females stop laying eggs;
• 45 – 50 ⁰C - lice and their larvae remain viable from several hours to 30 minutes;
• 50 – 55 ⁰C - adults die within a few minutes, the development of nits stops;
• 55 – 60 ⁰C - insects die almost instantly, the eggs remain viable;
• 60 ⁰C and above - nits are destroyed.

Interesting fact! Lice, it turns out, are preferred by people who regularly wash their hair! It is easier to move around clean hair, and besides, skin that is not contaminated with grease can be bitten off.

Cold effect

No less than the heat they fear the lice of the cold. Zero temperature causes them to a state close to shock. They cease to multiply, eat and practically do not move. In the eggs, the development of embryos ceases, and the larvae fall into a kind of hibernation.

Do lice die in the cold? It depends on whether they are on the human body, or away from it. Head and pubic lice, living directly on the surface of the skin, are better protected from the effects of the cold than their counterparts living in clothing.You can walk in the cold at least a whole day without a hat and earn inflammation of the brain, while the insects will feel great. Lice will likewise react to swimming in the ice hole. Rather, a person will catch a cold and go down with pneumonia, than these parasites will die.

A stable temperature is always maintained on the surface of the body. In particular, on hairy areas, as well as covered with clothing, it can range from +29 ⁰From to +34 ⁰C. Even on unprotected skin, the temperature never drops below zero. Therefore, it is practically not realistic to remove pests with frost, however, this technique will work perfectly against linen lice.

Critical minus temperatures for lice at a humidity of 70%:

• 0 – 5 ⁰C - insects do not multiply and stop feeding, the development of embryos in eggs is suspended;
• 5 – 15 ⁰C - lice die within a few minutes, nits remain viable;
• 15 – 20 ⁰C - almost instant death of both adult insects and their larvae at different stages of development;
• 20 ⁰Nits are killed from frost.

Advice! Head lice can be easily removed from wet hair. Therefore, with pediculosis, it is recommended to comb out the head with a frequent comb immediately after washing.

Methods of temperature exposure

The elimination of lice with the help of heat or cold has been actively practiced at all times. They do not lose their relevance to this day. Frost and heat do a great job where chemicals fail. However, they do not harm human health and are certain. The methods and methods of exposure are selected depending on the stage of development of the parasite and the place of its localization.

Freezing

Freezing is mainly used against linen lice. The following methods are used:

1. They hang clothes in frost at a temperature not higher than -20 ⁰With and hold so a few days. In this case, all adult insects and larvae die, but nits can remain, so the treatment is repeated after some time.
2. Infected items are put in a bag and placed for several hours in a chamber for quick freezing of food. At the same time, parasites are guaranteed to be destroyed at all stages of development, as well as their eggs.

The advantages of such methods are their safety for human health and sufficient effectiveness. In addition, they do not require any material costs and are available to any person.

Are body lice afraid of frost? As we have already found out, it is unlikely to be able to get rid of insects that live on the hairy areas of human skin. It is unrealistic to create at least zero temperature on the surface of the body without a health risk, so it is better to use heat against them.

Interesting fact! At a temperature of +10 - 20 ⁰With all the processes occurring in the body of lice, slow down, and they become able to do without food for 10 days. Therefore, “starvation” of insects by hunger at this temperature range is unlikely to succeed.

Heat exposure

Temperature above +50 ⁰C will help to get rid of both linen parasites and their relatives living directly on the human body. The following methods are practiced:

1. Infected clothes are put in a tub with water, and boil for an hour.
2. Things are washed in a machine at a temperature not lower than +60 ⁰FROM.
3. The linen is ironed with a hot iron. In this case, special attention is paid to folds and hem.
4. Body parasites are excreted with a hairdryer. To do this, treat the infected area of ​​the body with a hot stream of air, and then comb out the insects comb. This method is ineffective against nits, but allows you to get rid of adults. Under the influence of heat, lice lose their ability to cling to hair and remove it becomes very simple with a conventional comb.

The undoubted advantage of all methods of removing heat with lice is that parasites can be eliminated in a very short time with a single treatment. At the same time, every person can carry it out, and a positive result is guaranteed in most cases.

Interesting facts about lice, as well as ways to get rid of them can be found in this video: