Introduction: Heat waves have been related with lethal effects, especially in Europe during the intensely hot summer of 2003. However, besides increased deaths and ailments, there are no specific data on the psychiatric effects of heat waves.
Methods: We have compared psychiatric emergencies in Barcelona during a 15-day heat waves period with the rest of the 2003 summer days. The main variables of the study were total emergencies, admissions, diagnoses, Severity of Psychiatric Illness scale (SPI), psychosocial variables, treatment rendered (including use of restraints), and referrals.
Results: No differences were found in the number of emergencies and admissions. During the heat wave, there were more patients with psychiatric backgrounds, more diagnoses of alcohol and drug abuse, but fewer anxiety disorders. The proportion of patients with mechanical restraint increased, but this only occurred in half of the cases in patients with drug or alcohol abuse. The item "dangerousness toward others" (part of the SPI scale) scored significantly higher during the heat waves.
Conclusions: There were no significant increases or decreases in psychiatric emergencies or admissions. However, the heat wave was related to more violent behavior and higher drug and alcohol abuse. It should be noted that anxiety conditions and benzodiazepine prescriptions were lower during this period. These findings may be useful to implement medical-psychiatric preventive measures against the heat wave phenomenon.