You can’t pour out of an empty jug — and that’s health and safety
This is something I was never very good at.
Switching off the phone.
There is always one more vulnerable person.
One more case email to answer.
One more thing to do.
And the uncomfortable truth is: that feeling is not wrong. There often is one more thing.
But here is the part that took me far too long to learn:
Recharging your batteries is not optional.
It is an essential part of looking after others.
This is not only self-care. This is systems safety.
We often talk about rest as if it were a personal preference. Something soft. Something you can trade off against productivity.
It isn’t.
From a human factors perspective, rest is a functional requirement.
Your body operates through two interacting systems:
the sympathetic nervous system — activation, stress, action
the parasympathetic nervous system — recovery, repair, regulation
Under sustained demand, the sympathetic system dominates: heart rate increases, stress hormones such as cortisol and adrenaline are released, attention narrows, and the body is primed for action.
That is useful — for a while.
But recovery is not optional. It is where:
muscle tissue repairs and strengthens
the brain consolidates memory and processes information
stress hormones are regulated back down
attention and decision-making capacity are restored
Without sufficient recovery, performance does not just plateau — it degrades.
Cognitively, this shows up as:
reduced working memory
slower processing speed
increased reliance on shortcuts and assumptions
reduced ability to notice weak signals or emerging problems
In human factors terms: your error rate increases, and your ability to detect and correct those errors decreases.
The problem is that fatigue does not feel like failure.
It feels like:
“I can still push a bit more.”
And that is exactly what makes it dangerous.
In operational environments, this is well understood
In military and emergency response contexts, there is a reason for structured rest and decompression.
It is not just an excuse to sit in a tent and watch a bad movie. It is a controlled reduction in load to allow cognitive and physiological recovery. After sustained operations, people are deliberately taken out of the environment, given time, space, food, sleep, and reduced demands.
Not because it is nice.
Because it is necessary.
You cannot run high-load systems — human or organisational — without recovery and expect them to remain reliable.
The uncomfortable version
I say this to servicemen and rescuers often, and I will say it here as well:
If you are fatigued and exhausted, you are not help.
You are a liability.
If you go down, you are not a 0 or a -1 to the team.
You are a -2 at best, because at least one or two people now have to look after you.
If a stretcher is needed, you can very quickly become a -9 — and one of those will likely be a medic you have now tied up.
All of those resources are now gone from the original task.
From the casualty.
From the mission.
The safest and most professional thing you can do is say:
“Guys, I’m fatigued. I’ll step out.”
And step out. Bench yourself. That’s how you help.
Someone whose battery is still full can come in.
What to do about it
Knowing this is one thing. Acting on it is another.
There are three parts to this: monitoring, design, and culture.
1. Monitor yourself
Fatigue is difficult to self-assess because the system doing the assessing is the one that is degrading.
So you need simple checks.
A practical one:
Can you still clearly and quickly verbalise:
your name (long-term memory)
your service or staff number (mid-term / working memory)
where you are (situational awareness)
what you are doing right now (short-term / task focus)
This works because it spans multiple cognitive domains at once. If fatigue is creeping in, it usually shows up somewhere in that chain.
If that starts to slip — hesitation, word-finding, losing track — that is a warning sign.
You will often see “classic” fatigue tests suggested, such as:
counting backwards from 100 in 7s or 3s
estimating 10 seconds with your eyes closed
These can be useful — but they are not always reliable.
They depend heavily on your baseline abilities. If you already find numbers, sequencing, or time estimation difficult (for example due to dyscalculia, dyslexia, or different cognitive styles), these tests can give misleading results even when you are well-rested.
So the question is not:
“Am I good at this?”
It is:
“Am I worse at this than I usually am?”
You are not testing intelligence. You are testing degradation.
Other indicators:
rereading the same sentence multiple times
losing track mid-task
increased irritability or unusually low tolerance
defaulting to “I’ll just push through”
These are not personality changes. They are system signals.
Take them seriously.
2. Build redundancy
A system that relies on one person continuing indefinitely is not a safe system.
Simple test:
Is there a backup for what this person is doing right now?
If the answer is no, then the system is already fragile.
Either:
the task is not critical and can be paused, no harm done
or it is critical — in which case it needs a deputy, a handover point, or shared ownership
Redundancy is not inefficiency. It is what makes systems resilient under load.
3. Build a culture where stepping back is normal
People will not step back if it is seen as weakness.
They will step back if it is seen as professionalism.
That culture does not come from policies. It comes from behaviour.
Leadership needs to:
openly call fatigue in themselves
step back visibly
hand over without drama
That signals:
This is safe.
This is expected.
This is how we keep the system working.
If stepping back costs someone status, they will not do it — and the system will fail later, at a higher cost.
And this applies far beyond rescue and military work
It applies to:
casework
teaching
management
policy work
any role where people depend on you functioning well
If you are running on empty, your ability to:
think clearly
communicate precisely
make good decisions
and notice when something is going wrong
is already compromised.
You do not stop helping when you rest.
You make your help reliable again.
So yes
There is always one more email.
One more person.
One more thing to do.
But if you are exhausted, you are no longer solving the problem.
You are becoming part of it.
So go home, cuddle the pet, watch the tv show, walk in nature, game with friends… this is looking after other people.