Tiredness, also known as Sleep Deprivation, is a status effect that is caused to a family member if he/she goes to scavenging frequently. To cure someone from being tired, the player should feed them frequently, and this is costly. Mutant Mary Jane can't get tired. A member may also get tired if the player gets the sleeping event and he/she doesn't give the medkit to the members in the fallout shelter.
Tired members will be unable to go scavenging. Tired members may look similar to fatigued members, but there are noticeable differences. Ted's face will fall and his mouth is open if he's tired for too long (this doesn't happen if he's insane too). Dolores will have narrower eyes and look dirty. Mary Jane will look dirty and slouch on her arm. Timmy will look ahead and have sleepy eyes. All in all, being tired is bad.