OBJECTIVES: Head lice (Pediculus humanus capitis) are a major irritant to children and their parents around the world. Each year millions of children are infested with head lice, a condition known as pediculosis, which is responsible for tens of millions of lost school days. Head lice have evolved resistance to many of the currently used pediculicides; therefore, an effective new treatment for head lice is needed. In this study we examined the effectiveness of several methods that use hot air to kill head lice and their eggs. METHODS: We tested 6 different treatment methods on a total of 169 infested individuals. Each method delivers hot air to the scalp in a different way. We evaluated how well these methods kill lice and their eggs in situ. We also performed follow-up inspections to evaluate whether the sixth, most successful, method can cure head louse infestations. RESULTS: All 6 methods resulted in high egg mortality (> or = 88%), but they showed more-variable success in killing hatched lice. The most successful method, which used a custom-built machine called the LouseBuster, resulted in nearly 100% mortality of eggs and 80% mortality of hatched lice. The LouseBuster was effective in killing lice and their eggs when operated at a comfortable temperature, slightly cooler than a standard blow-dryer. Virtually all subjects were cured of head lice when examined 1 week after treatment with the LouseBuster. There were no adverse effects of treatment. CONCLUSIONS: Our findings demonstrate that one 30-minute application of hot air has the potential to eradicate head lice infestations. In summary, hot air is an effective, safe treatment and one to which lice are unlikely to evolve resistance.