The next pandemic will likely emerge from one of the large and well-known families of respiratory viruses. Measuring the extent to which these viruses can spread via small droplets, large droplets, or direct contact is crucial. However, measuring and quantifying airborne viruses is notoriously difficult. Numerous external factors are of influence, including temperature and humidity levels. If we gain a greater understanding of the route of transmission of respiratory viruses, we can work on strategies to reduce that spread.