Dr. May Chu, a clinical epidemiology professor at the Colorado School of Public Health, said that as a public health practitioner, she'd never say an event is "totally safe," but right now, it seems reasonable to "congregate outdoors and have a good time." "I think a few caveats is that if you're not vaccinated, then you do need to be careful not to be so close (to people) so that you put yourself at risk for being exposed," said Chu, who said that she would still advise unvaccinated people to wear masks when mixing with groups from outside their household. "... In general, the rule of thumb is that it's a green light, with a few considerations."