How do I simulate a remote web site taking a long time to respond before eventually timing out?

I’m using Mac Yosemite. I want to simulate making a request for a web site in which the request will time out after an extended period of time (I don’t care about how much time, 30 seconds, 1 minute, 5 minutes, whatever). I would like to simulate this on the following web address

http://ift.tt/24cE1XH

And so I added this to my /etc/hosts file

10.255.255.2    assets.adobedtm.com

However now upon making a request for the web page, the request aborts immediately without spinning for a little bit and then eventually timing out. I observe this on both Firefox and Chrome. How can I simulate the request timing out (as if the remote server is really slow to respond) without dying immediately?