my $filename = 'tested.csv';

open my $FH, $filename
  or die "Could not read from $filename <$!>, program halting.";

# Read the header line.
chomp(my $line = <$FH>);
my $i = 0;
$line = join '', grep { $i++ % 2 ? {s/,/ /g} : 1} split /"/,$line;
my @fields = split(/,/, $line);
print Dumper(@fields), $/;

my @data;
# Read the lines one by one.
while($line = <$FH>) {