Abstract Body (Do not enter title and authors here):
Introduction:
Seasonal variations, particularly cold weather, can increase the risk of acute coronary syndrome, as evidenced by various studies over the years. On the other hand, hot weather can cause dehydration, electrolyte imbalances, and thermoregulatory strain on the heart, leading to adverse cardiac events. In recent years with rising concerns about global warming, we aim to study the impact of climate changes during the summer on outcomes among people hospitalized with ACS.

Methods:
We used the National Inpatient Sample from 2016 to 2020 to identify young adults hospitalized with ACS using appropriate ICD-10 codes. Patients were categorized into two cohorts: summer (hospitalizations during June, July, and August) and non-summer (hospitalizations during other months). The outcomes studied were ACS hospitalizations and in-hospital mortality. Pearson chi-square tests and the Mann-Whitney U test were used for cohort comparisons.

Results:
Of 230,555 ACS hospitalizations, 26.2% (n=60,340) occurred during the summer months, with a median age of 40 years. White individuals had higher hospitalization rates compared to others (57.8% vs. 58%), and those from lower socioeconomic statuses had higher ACS hospitalizations in both cohorts (37.5% vs. 38.1%). Comorbidities like hypertension, diabetes, and hyperlipidemia were lower in the summer cohort (all p<0.001). The rates of in-hospital death were higher in the summer cohort compared to the non-summer cohort (4.7% vs. 4.5%, p=0.019). However, logistic analysis showed no significant association between summer climate and ACS hospitalizations (OR 1.02, 95% CI 0.99-1.04, p=0.178) or all-cause mortality (OR 1.04, 95% CI 0.94-1.06, p=0.446), irrespective of region or gender.

Conclusion:
While in-hospital mortality rates were higher during the summer months, there was no significant association between summer climate and the incidence of ACS or all-cause mortality, regardless of region or gender, when adjusted for confounding factors.