Summer heat, outdoor fun ... and cold and flu symptoms? The three may not go together in many people's minds: partly owing to common myths about germs and partly because many viruses really do have lower activity levels in the summer. But it is possible to get the sniffles — or worse — in the summer. Federal data released Friday, for example, shows COVID-19 is trending up in most states, with emergency department visits up among people of all ages. Here's what to know about summer viruses. How much are colds and flu circulating right now? The number of people...