O'Hare International (ORD)

A published minimum connection time is the point below which a connection is impossible, not the point above which it is comfortable. It assumes both flights run on time, that you do not clear immigration, and that your gates are not at opposite ends of the airport.

Before accepting a connection here, check:

• Whether you change terminal, and how the transfer works.
• Whether you clear immigration and re-check bags — connecting through a country you are entering means queueing twice.
• Whether it is one ticket or two. On two separate tickets a missed connection is your cost, not the airline's.
• Whether it is the last departure of the day, which turns a delay into an overnight.

More on this in what to check before you book a connection.