Exhausted

Some special abilities and environmental hazards, such as starvation and the long-term effects of freezing or scorching temperatures, can lead to a special condition called exhaustion.
This condition is cumulative. Each time you receive it, you gain 1 level of exhaustion. If your exhaustion level exceeds 10, you die.
If you have 1 or more levels of exhaustion, you are considered exhausted. While exhausted, you suffer the following effects:

• Your Ability Checks, Attack Rolls, and Saving Throws are reduced by an amount equal to your exhaustion level.
• Your Spell and Maneuver Save DC is reduced by an amount equal to your exhaustion level.
• You cannot Dash if your exhaustion level is greater than 5.

An effect that removes exhaustion reduces its level as specified in the effect's description, with the exhausted condition ending if a creature's exhaustion level is reduced below 1.
Finishing a long rest reduces a creature's exhaustion level by 1. Also, being raised from the dead reduces a creature's exhaustion level by 1.