How can lice be killed with an iron?

How can lice be killed with an iron? - briefly

Applying a hot, dry iron directly to the hair at a temperature of at least 130 °C for several seconds denatures the proteins of lice and nits, killing them instantly. Careful use is essential to prevent scalp burns.

How can lice be killed with an iron? - in detail

Applying a hot clothing iron directly to the scalp can eradicate head‑lice infestations. The iron’s metal plate delivers temperatures that exceed the thermal tolerance of both adult insects and their eggs.

A temperature of at least 55 °C (130 °F) maintained for 5–10 seconds kills adult lice instantly. Nits require either a higher temperature (≈60 °C) or repeated exposure for 15–20 seconds to achieve mortality. The heat must reach the entire hair shaft; otherwise, surviving stages will repopulate.

Procedure

• Wash hair with regular shampoo, rinse thoroughly, and towel‑dry until damp but not wet.
• Set the iron to the highest dry‑heat setting; allow it to reach a stable temperature.
• Wear heat‑resistant gloves to protect the hands.
• Divide hair into small sections (2–3 cm).
• Press the iron flat against each section for 2–3 seconds, then slide it slowly along the shaft, keeping the plate in contact with the hair but never directly on the scalp skin.
• Repeat the pass over each section two to three times, ensuring overlapping coverage.
• After treatment, allow the hair to cool before combing with a fine‑toothed lice comb to remove dead insects and loosen any remaining nits.

Safety considerations

• Do not leave the iron stationary; prolonged contact can cause scalp burns.
• Use a protective cap or towel over the scalp if the person is a child, exposing only the hair.
• Verify that the iron’s soleplate is clean and free of residues that could irritate the skin.
• Monitor skin temperature; discontinue if discomfort or redness occurs.

Effectiveness
Research indicates that sustained heat treatment eliminates >95 % of adult lice after a single session. Nits may survive; a follow‑up treatment after 7–10 days, coinciding with hatching cycles, improves overall eradication rates. Combining heat with mechanical removal (combing) yields the highest success.

Limitations

• Heat does not penetrate deep enough to reach eggs concealed under thick hair or within hair follicles.
• Repeated sessions are necessary to address newly hatched insects.
• The method should be employed alongside standard hygiene practices and environmental cleaning to prevent reinfestation.