For this study, KCL says researchers examined nearly 7,000 hospitalized patients with coronavirus in Croatia, Spain, Italy, Finland, Poland, Germany, the UK, and China. “Mapping this information against local temperature and estimated indoor humidity revealed that severe COVID-19 outcomes (hospitalization, admittance to ICU or need for ventilation) decreased in most European countries over the course of the pandemic, covering the transition from winter to early summer,” according to KCL.ae0fcc31ae342fd3a1346ebb1f342fcb Not only was the severity of symptoms lessened—so was the death rate. The study found that as temperatures went up, deaths went down in most European countries that experienced the coronavirus pandemic over the course of multiple seasons. However, “the severity of symptoms and mortality rate remained constant in China during the first wave of the pandemic, which occurred solely throughout the winter,” according to KCL. While COVID-19 is not completely hindered by heat—as it did spread in hot, humid countries throughout East Asia–“it is notable that the severity and mortality from the disease have been lower than in Europe and other more temperate climates,” KCL noted. This is not the first time we’ve heard about heat’s effect on COVID-19. In May, the World Health Organization (WHO) found that “heat at 56°C [132.8°F] kills the SARS coronavirus at around 10000 units per 15 minutes.” Although the SARS coronavirus is different from COVID-19, the two viruses behave similarly, which led experts to believe COVID-19 would be affected by heat in the same way SARS is. The study performed at KCL gives experts insight into how temperatures might affect COVID-19. Gordan Lauc, PhD, lead author of the study, said, “Our findings point to a role for seasonality in the transmission and severity of COVID-19, and also argue for increased humidity and hydration as a way to combat the virus.” Back in June, Stephanie Taylor, infection control consultant at Harvard Medical School, told Fast Company that keeping the humidity levels in your home between 40 and 60 percent (the current recommendation from the Environmental Protection Agency) could help fight the spread of the coronavirus. Increased humidity won’t necessarily kill COVID-19 in the air, but it can help keep it bay, according to Taylor’s studies. RELATED: For more up-to-date information, sign up for our daily newsletter. Temperature and humidity are only one piece of the puzzle. Discovering and learning about the various aspects that affect the virus is essential to getting a full picture of the disease. In the KCL write-up of the study, professor Tim Spector, MD, said, “By understanding the many factors that contribute to the severity and spread of the disease, we can implement effective measures to control it over the coming months.” And for more information on coronavirus mortality, More Than Half of States With Rising COVID Deaths Have This in Common.