$hash = { 'foo.bar' => 'foo.bar_v', 
          'foobar'  => 'foobar_v' 
};
print $hash->{foo.bar};
__DATA__
foobar_v   <-- note we have lost the . in the key so get the wrong value

##</code><code>##

$VAR1 = 
{ 
    'wellmed' => {  'wellmedack' => {}, 
                    'wellmed.ack' => {  'errors' => '0', 
                                        'wellmed.response' => 'User data updated for ID: aac20fd41e07ea11d9bfc1ac192a16aa77', 
                                        'responses' => '1' 
                                     } 
                  } 
};

print "Response: ", $VAR1->{'wellmed'}->{'wellmed.ack'}->{'wellmed.response'},
      "\nErrors: ", $VAR1->{'wellmed'}->{'wellmed.ack'}->{'errors'},