There are numerous situations when mountaineers may have to bivouac.
A few of them are exceptionally not advised but unavoidable at the same time.
I was going through the details of the K2-Tragedy(2008) and I learnt that in situations where one runs out of time and doesn't want to give up the summit bid, one may end up in a situation when he/she has to bivouac.
I am absolutely not in the mind to do something like what Marco Confortola and Gerard MacDonell or Wilco Van Rooijen did.
What can one do to prepare for such a bivouac? What are things that one should look for in case if he/she/they are going to have to Bivouac?
I believe that when one realizes that he/she has to bivouac, it is pretty late and the sun has set already.
Edit: Lets take this question into consideration Spectifically for High Altitudes.