On average, more Americans visit the emergency room on July 4 and 5 than any other day during the year, making it "by one measure, the most dangerous day of the year," according to the Pew Research Center. First responders are already stretched thin by the coronavirus pandemic, leaving some cities and towns worried about this year's Independence Day holiday, particularly when it comes to ER visits and the availability of first responders. In Houston, a reported 307 firefighters are in quarantine for COVID-19 on the morning of July 4, leaving the department close to 100 short of a usual holiday shift, according to the local ABC affiliate. Visit Business Insider's homepage for more stories. A double whammy of the coronavirus and a typical surge in emergency room visits around the US Independence holiday is leaving local governments with tough decisions in emergency management.