Abstract The aim of this paper is to study the relation- ships between hospital emergencies and weather condi- tions by analysing summer and winter cases of patients requiring attention at the emergency room of a hospital in the city of Buenos Aires, Argentina. Hospital data have been sorted into seven different diagnostic groups as follows: (1) respiratory, cardiovascular and chest-pain complaints; (2) digestive, genitourinary and abdominal complaints; (3) neurological and psychopathological dis- orders; (4) infections; (5) contusion and crushing, bone and muscle complaints; (6) skin and allergies and (7) miscellaneous complaints. In general, there is an in- crease of 16.7% in winter while, for group 2 and group 6, there are more patients in summer, 54% and 75% re- spectively. In summer, the total number of patients for group 6 shows a significant positive correlation with temperature and dew-point temperature, and a negative correlation with the sea-level pressure for the same day. In winter, the same relationship exists, however its corre- lation is not as strong. The lags observed between these three variables: maximum dew-point temperature, maxi- mum temperature, minimum air pressure and the peaks in admissions are 1, 2 and 4 days respectively. In winter, increases in temperature and dew point and decreases in pressure are followed by a peak in admissions for group 2. In winter, there are significantly more cases in group 5 on warm, dry days and on warm, wet days in the summer. Keywords Weather · Emergency room patients · Argentina Introduction The relationship between weather and symptoms of dif- ferent pathologies has been studied worldwide, although less extensively for Argentina. For example, there is now evidence of a worldwide increase in the occurrence of asthma and other allergic diseases especially in industrial societies (see, for example, Rosas et al. 1998: Galán et al. 2000). Such an increase is related to anthropogenic and weather factors and especially to extreme weather events. In particular, some studies relate extreme heat waves to mortality (Ellis and Nelson 1978; Marmor 1975; Gover 1938; Nakai et al. 1999; Kloner et al. 1999). A frequent criticism of weather/mortality studies points to certain cultural adjustments that may have an impact on these relationships, such as the reduced expo- sure to extreme weather conditions as a result of the in- creased use of air conditioning (Kalkstein and Davis 1989). Other weather/health studies may be cited, like that of McGregor et al. (1999), who found a relationship between weather conditions and admissions due to respi- ratory diseases in the United Kingdom. However, few studies have examined the relationship between weather conditions and various diseases in Argentina, since specific databases are non-existent. Most previous studies have focused on specific diseases like asthma. Hoffmann et al. (1983) carried out a de- tailed year-long study on asthmatic patients in Rosario, Argentina. They found an increase in asthma cases coin- cident with the start or the end of different synoptic situ- ations, like a 500-hPa trough. Piccolo et al. (1988) deter- mined the relationship between asthma emergency cases and meteorological variables in Bahía Blanca, in Southern Argentina. Rusticucci et al. (1996) related hospitalisation of various causes with meteorological variables. They found a close relationship between the persistence of high minimum temperatures and the num- ber of hospitalised cardiovascular patients. Currently the work aims to determine the relationship between emergency room cases and weather types at the emergency room of “La Sagrada Familia”, a hospital in M. Rusticucci ( ✉ ) · M. L. Bettolli Departamento de Ciencias de la Atmósfera y los Océanos, Universidad de Buenos Aires, Ciudad Universitaria – Pab. II, (1428) Buenos Aires, Argentina e-mail: mati@at.fcen.uba.ar Fax: ++54-11-4795-5033 M. de los Angeles Harris Clínica “La Sagrada Familia”, Buenos Aires, Argentina Int J Biometeorol (2002) 46:42–51 DOI 10.1007/s00484-001-0113-z ORIGINAL ARTICLE Matilde Rusticucci · M. Laura Bettolli M. de los Angeles Harris Association between weather conditions and the number of patients at the emergency room in an Argentine hospital Received: 20 November 2000 / Revised: 10 September 2001 / Accepted: 19 September 2001 / Published online: 4 December 2001 © ISB 2001