To the Editor.—
Our x-ray film identification apparatus recently became intermittently inoperative. I replaced the battery and put the old one (a 9-volt transistor battery with exposed posts) in my pocket, planning a follow-up examination later, since the cause of the problem was obscure. After approximately 15 minutes, a slight heat sensation was noted along the upper lateral aspect of my left thigh. The heat sensation continued intermittently and definitely increased in intensity. It became unbearable after approximately 30 minutes, and an examination of the area was definitely indicated.My pants pocket felt quite warm as I began removing loose change before undressing. I withdrew five pennies, four nickels, four dimes, and two quarters, and then burned my hand on an extremely hot battery.A focal area of erythema of approximately 3.5 cm in diameter was present on the thigh immediately beneath the inferior aspect of my left-front pants pocket.