The dogs will be able to transition easily, but the handlers are going to need to get out of the Rally-O mind frame when entering an obedience ring. Much less talking, no body language aside from hand signals (in Rally-O you can stear with your body to encourage very intricate heeling patterns), etc.
Lilies in the late July heat, Lemnos, Greece. The dog days or dog days of summer are the hot, sultry days of summer. They were historically the period following the heliacal rising of the star Sirius, which Greek and Roman astrology connected with heat, drought, sudden thunderstorms, lethargy, fever, mad dogs, and bad luck.
When I was a kid I would hear that it is the dog days of summer in Texas during times of persistently hot weather in the summer. I assumed that the term dog meant that outdoor dogs suffered from all the heat day after day. Life for an outdoor dog just can not be fun on those 95 F and hotter days that repeat in the summer.