Smoke exposure due to wildfires has been shown to exacerbate those with cardiovascular and respiratory diseases and increase incidence of emergency department (ED) visits for those diseases. During the week of October 21-28, 2007, seven wildfires burned throughout San Diego County exposing the population to the effects of smoke. This was a large scale event that affected the entire county and burned over 360,000 acres of land, causing 515,000 advised and mandatory evacuations within the county. The purpose of this historical prospective study was to assess the relationship between race/ethnicity and whether a patient had visited the ED prior to the fires for cardiovascular or respiratory diseases and examine the incidence rates for each time period for cardiovascular and respiratory diseases. The final purpose of this study was to examine what impact the fires had among those with underlying cardiovascular and respiratory diseases and to characterize their health care seeking behavior at EDs prior to the fires and see how they were impacted during the wildfires using the BioSense dataset. Within the pre-fire population, African Americans and Hispanics were significantly associated with being seen for cardiovascular or respiratory diseases. There were 181,560 total visits in the pre-fire period, 3,685 in the fire period, 14,547 in the post-fire period, and 866 in the Santa Ana period. Both cardiovascular and respiratory diseases incidence rates significantly increased from pre-fire to fire period and pre-fire to post-fire period. There were 139,757 unique patients who were seen during the pre-fire period, of whom 1,127 (0.8%) followed through to the fire period and 3,800 (2.7%) followed through to the post-fire period. A patient who utilized the ED in the pre-fire period for respiratory diseases was significantly associated with returning in both the fire and post-fire periods. This study concludes that the wildfires of 2007 did show exacerbation of the populations of people with cardiovascular and respiratory diseases and there was a population that was more likely to be exacerbated.