my $temp;
while (<>) {
  chomp;
  if (s/^Temp:\s*//) {
    if (defined($temp)) { ...use $temp... };
    $temp = $_;
  } else {
    $temp .= $_;
  }
}
if (defined($temp)) {
  ...use $temp...
}

##</code><code>##

while (<>) {
  next unless m{(\d+)/$};
  my $temp = $1;
  ...use $temp...
}

##</code><code>##

while (<>) {
  next unless /^Temp:/;
  my $temp;
  if (m{(\d+)/$}) {
    $temp = $1;
  } else {
    $_ = <>; # read the next line
    next unless m{(\d+)/$};
    $temp = $1;
  }
}