To the Editor: During the recent Persian Gulf war, there were 18 missile attacks from western Iraq on scattered areas in Israel. The fear of chemical warheads resulted in the preventive use of gas masks by the Israeli population for variable periods after each alarm. We would like to report some of the medical complications that were associated with the wearing of gas masks. Seven people were reported to have died of asphyxia because of their failure to remove the protective plastic seal on the gas-mask filter. Lesser degrees of transient hypoxia were noted, especially in persons with cardiopulmonary disorders.