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

What other kinds of lines are in your file? Would this work:

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

This just looks for lines that end in a string of digits followed by a slash and assumes it's the information you're looking for.

If it is necessary to find the Temp: prefix on the same line or the line before, then this should work:

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