Generally, password expiration is used to force users to change their passwords. What it sounds like you want to do is to lock the account, which prevents all login.
What I would suggest you do instead is, when you create the account, also set up an at job which will lock the account after four hours.
For example:
useradd temp8143
echo chage -E 0 temp8143 | at now + 4 hours
(chage -E expects expiration dates to be given in days, so we work around this with an at job.)