Stress is an emergency management issue.

All minds and bodies have limits, beyond which they do not perform well. According to Daniel Kahneman in his book “Thinking, Fast and Slow” many psychological studies have demonstrated that people who have been stressed mentally and physically fall prey to poor behaviors:

• They are more likely than unstressed people to yield to temptation. (The study involved a chocolate cake instead of a bowl of fruit, but one might believe that stressed firefighters and cops might give in to other temptations, such as engaging in risky behaviors, after several stressful overtime shifts.)
• They are more likely to make superficial judgements, and exhibit less self-control over crude comments.
• Those who, in experiments, were instructed to stifle their emotional reaction to an emotionally charged movie performed worse on tests of physical strength than those that were not instructed to suppress their reaction.

These are all examples of what psychologists call “ego depletion” – the phenomenon of being less able to react peacefully to provocation, to be less likely to resist temptation, to perform worse on physical and cognitive tests and logical decision-making, after they have experienced significant mental and/or emotional stress.

While these tests have not been applied specifically to law enforcement officers and firefighters, nurses, and air traffic controllers, one can easily infer that repeated stressful shifts, with insufficient time to recover in between, will produce similar results. Firefighters will have less strength; cops will react more quickly and with less self-control to provocations. Nurses will miss errors in medication; air traffic controllers will fall sleep on the job. Cultural paradigms of stifling emotional reaction to stressful experiences (i.e., “Just suck it up and get back to work”) add to these debilitating factors.

As you might expect, there are also strong connections between blood glucose levels and cognitive and emotional behavior. Subjects in an experiment requiring great mental concentration performed differently based on their consumption of glucose before and during the experiment. Those that drank lemonade sweetened with glucose performed measurably better than those that drank lemonade sweetened with an artificial sweetener. I wonder how many injuries occurred because no one handed out candy bars to tired workers.

In one study, judges evaluating parole applications were given those applications in random order over several days, and their decisions were recorded and plotted against the three breaks they took each day to replenish their strength. While the overall average approval rate was about 1/3 (35%), the rate dropped to near zero right before breaks, and soared to 65% after the breaks. Blood glucose levels impact critical thinking, and maybe impact empathy.

It's not a long leap to consider how many more cops and protestors are injured on the third day of tense protests, just because those cops have had less sleep, less food, and have been exposed to more stress over the preceding days. The only solution to this is rest for the officers, and the only way to provide them with more rest is to have more law enforcement officers available, either on that department’s rolls, or through mutual aid from nearby agencies.

Fatigue and stress kill, and they don’t just kill those who are fatigued. They kill those with whom exhausted people come in contact with: their patients, their family members, their colleagues, and strangers who share the road with them.