BackgroundCellulitis is a common infection of the skin and subcutaneous tissue. Meteorological and environmental temperatures were previously identified as potential risk factors for causation and the patient's odds of hospitalization. In this regard, we aim to study the pattern of cellulitis during 10 Hajj seasons and examine the impact of changing seasonal temperatures and overall pilgrim populations as potential risk factors. MethodologyIn-hospital cellulitis was studied within the context of the Hajj. A retrospective review of pilgrim patients coded for cellulitis was undertaken for the Hajj seasons between 2004 and 2012. Possible roles of environmental temperatures, pilgrim population sizes, and ethnicity were examined as potential risk factors. ResultsA total of 381 patients belonging to 42 nationalities were identified, with 285 (75%) males and 96 (25%) females with a mean age of 63 years. On average, cellulitis accounted for 23.5% of general surgical admissions with proportional increases from 2004 to 2012 (r = 0.73, p = 0.016), which significantly correlated with the rise in seasonal temperatures (r = 0.7, p= 0.023). ConclusionsThe findings of this study identified cellulitis as a significant health risk during the Hajj, which is likely to be prevalent in warmer seasons. Our results may assist clinicians in educating Hajj pilgrims of different nationalities about the increased risk of cellulitis during warm seasons and possible predisposing environmental factors of infection.