In the book Rework by Jason Fried and David Heinemeier Hannson, the authors say that ASAP, "devalues any request that doesn't say ASAP. Before you know it, the only way to get anything done is by putting the ASAP sticker on it." They go on to explain that most things just don't warrant that kind of hysteria. Nobody is going to die, it won't be the end of the world if it's not done this instant.
They say what it will do is create artificial stress, which can lead to burnout or worse. So, "reserve your use of emergency language for true emergencies."