What do heat, humidity and train malfunctions mean in Washington, DC? Summer, of course. The 97 -degree temperature this week meant substantial delays as one train after another succumbed to the heat. And if that's not enough, an unusually large number of tourists decided to travel during rush hour. Now, don't get me wrong, those of us who live and work in DC actually like tourists, just not at rush hour. As we are rushing to catch the next train, we don't want to be stopped by someone who thinks the architecture is especially nice at a particular station or by someone who doesn't know how to use the ticket machines. Save that for after 9 am and before 4 pm. On the other hand, if you want to get an insider glimpse as to what it's really like to be a city commuter, try hitting Union Station at about 7:30 am or 4: 30 pm.