We report here the case of a 12-year-old boy with erythema ab igne on his left thigh caused by the use of a laptop computer. This is the youngest of the 10 reported patients with this laptop-induced dermatosis since its first description in 2004. Erythema ab igne is a reticular, pigmented, sometimes telangiectatic dermatosis that is caused by prolonged exposure to a heat or infrared source. In laptop-induced erythema ab igne, the localization on the thighs and asymmetry are characteristic. The heat originates from the optical drive, the battery, or the ventilation fan of the computer.