Purple Status

I thought I had seen somewhere in the MAN pages about the ability to set
hosts so that if it is not responding to ping then all of the other
monitored services should not also send an alert because they are dependent
on the ping working.
 
If one of my machines goes offline because someone turns it off I don't want
the other services to also send me e-mails of their failure or purple
status.  How do I set alerting that if the connection is lost the other
services won't alert also.
 
Any ideas?
 
Thanks,
Jason