How to break out of hung or waiting telnet session in shell script?

I have to put together telnet instructions for 100s of hosts for verifying basic connectivity and get output in a neat format.

Problem- If a telnet is hung with message "Trying .... <hostname" due to firewall or routing issue the commands waits for a very long time before it times out and my shell script gets to execute next command. Please advise how to breakout of such hung telnet and resume on next line.

timeout 1s telnet blah blah

rdrtx1's answer is correct and useful for linux. If you don't have linux please let us know what UNIX and version you do have.