$tmp[5] = "BCInletTemperature = 90[C]";
print "$tmp[5] xx\n";
$temp = $tmp[5] =~ m{ = \s+ ($RE{num}{real}) \[ }xms;
print "xxx $temp xxx\n";

##</code><code>##

Name "charnames::CARP_NOT" used only once: possible typo at /usr/lib/perl5/5.18.2/Carp.pm line 437.
Name "Regexp::Common::delimited::CARP_NOT" used only once: possible typo at /usr/lib/perl5/5.18.2/Carp.pm line 437.
      BCInletTemperature = 90[C] xx
xxx 1 xxx

##</code><code>##

perl --version

This is perl 5, version 18, subversion 2 (v5.18.2) built for x86_64-linux-thread-multi