# hash of hashes
$hRecords{$key}{min} = $minSoFar;
$hRecords{$key}{max} = $maxSoFar;

# hash of arrays
$hRecords{$key}[0] = $minSoFar;
$hRecords{$key}[1] = $maxSoFar;

# or better (self documenting; less error prone)
my $MIN_IDX=0;
my $MAX_IDX=1;

$hRecords{$key}[$MIN_IDX] = $minSoFar;
$hRecords{$key}[$MAX_IDX] = $maxSoFar;