use strict;
...

foreach my $user (sort { $user_hash{$a}[0] <=> $user_hash{$b}[0] } 
                  keys %user_hash)
{
    my ($age, $height, $weight) = @{ $user_hash{$user} };
    print "User $user (age $age, height $height, weight $weight)\n";
}
[download]

-ben