I suspect by avast standard the OP means avast free, so no firewall other than what they have installed.

@ bioro
Free wifi, isn’t secure and it is possible that others could snoop on the communication between your system and what is a public wifi. So the links given by .: L’ arc :. are very useful to at least make you aware of the potential dangers.

A word about HTTPS Everywhere mentioned in one first of the articles given by .: L’ arc :., is that it forces https even on normal http pages. This means that the web shield isn’t going to be monitoring that activity, you could be less well protected from infection, something to consider.

Other links worth a look:
http://blog.avast.com/2013/07/19/traveling-computer-security-tips/
http://blog.avast.com/2013/07/08/security-tips-from-avast-forum-evangelists/

Stay safe.