Adversity stems from the adjective adverse. When things occur that upset you,  either potentially or actually, leading to a  harmful and unfavorable impact.

The difficulties or misfortune you experience are typically not planned (who plans for adversity to occur) and usually are things that were either accidents (e.g. car accident) or events out of your control (e.g., an injury to a loved one).

Remain Calm

During the second world war as part of preparations for a potential invasion, the English government began preparations for a media campaign focused on maintaining the morale of the populous.

The famous slogan, which has been widely transformed into a variety of current popular inspirational messages, was “Keep calm and carry on”

The simple point was anxiety, panic, and despair or even deep sadness have little effect in times of adversity.  By focusing on the mundane and the normal, it is possible to adapt to the adverse circumstances.

Carry On

The remain calm portion of the slogan does not refer to ignoring or pretending the difficult circumstances do not exist.  Rather the intent of the slogan is to encourage focusing on the things you can control (i.e., carry on)

These ongoing actions could well include proactive measures to resolve the adverse situation or just personal protective measure to minimize personal harm.

The key is not to react in a way that does more damage than repair.  The grieve you feel should not be hidden away to eat at your insides and ultimately paralyze you but it should be acknowledged.

Figure out how to deal with the adverse conditions in the best way possible, recognize perseverance is of great value and believe that ultimately the misfortune will be overcome.