First Aid · Common Situations
Eye injuries, hyperventilation, nosebleeds, blisters, fainting, and diabetic emergencies — none of them are rare, and each one has a first response that most people either don't know or get backwards.
Foreign objects in the eye
A speck of dust, a metal shaving, a wood chip, a grain of sand — foreign objects in the eye are common and often resolve quickly with the right response. They can also cause significant corneal damage if the natural response — rubbing — is followed. Rubbing grinds the particle against the corneal surface and turns a minor irritation into a deeper scratch.
Most small, loose particles can be flushed out with water or saline. The key is distinguishing between a particle that's sitting on the surface versus one that's embedded — and never trying to remove an embedded object yourself.
Do not let the person rub the eye
This is the first and most important intervention. Rubbing pushes the particle deeper and across the corneal surface. Gently hold or remind the person to keep their hands away.
Have the person blink several times
Blinking stimulates tear production, which may wash the particle to the inner corner of the eye where it can be safely removed or drain naturally.
Remove contact lenses if easy to do
Contacts can trap particles against the cornea and make flushing less effective. Remove them if the person can do so without discomfort — don't force it if lens removal itself seems to cause pain.
Flush with clean water or sterile saline
Have the person hold their eye open over a sink and let a gentle stream of clean room-temperature water run across the eye from the inner corner outward. Or use a sterile saline eye wash bottle with a direct rinse tip. Continue for several minutes.
Seek medical care if the particle doesn't clear
If flushing doesn't resolve the sensation within a few minutes, or if pain continues after the particle appears gone, or if vision seems affected — see a doctor. A corneal abrasion can cause persistent discomfort and needs evaluation. Metal particles in particular require prompt removal as they can oxidize and stain corneal tissue within hours.
Embedded objects — never attempt removal
If an object is embedded in the eye — a sliver of metal, a fishhook, a splinter — do not attempt to remove it. Do not flush aggressively. Cover the eye loosely with a sterile pad or clean cloth (never apply pressure), cover the other eye too if possible to reduce eye movement, and get emergency medical care immediately.
Eye protection
Most workshop and outdoor eye injuries are preventable with safety glasses or goggles. The barrier between a flying metal chip and the cornea is literally a pair of $8 safety glasses. Keeping them at the workbench, in the toolbox, and in the outdoor kit is the most effective eye protection available.
Regular prescription glasses are not safety glasses — they lack the side protection and impact rating of purpose-made eye protection.
For outdoor dusty environments, construction, yard work, or any task with projectile risk: glasses on before starting, not after something lands in the eye.
When to go to the ER vs. urgent care
ER immediately: Embedded object, chemical exposure, significant pain with or without a visible foreign body, any vision change
Urgent care same day: Persistent discomfort after successful flushing, sensation that something is still in the eye, mild redness that isn't improving
Monitor at home: Mild irritation that resolves completely within minutes of flushing and leaves no pain or visual disturbance
Chemical splash in the eye
A chemical splash to the eye is a time-critical emergency. Every second the chemical remains in contact with the eye continues to cause damage. Do not stop to call for help, remove contact lenses, or look up the chemical before beginning to flush — start the water immediately.
This topic is also covered in the Burns & Electrical Injuries page under chemical burns. The protocol is the same regardless of which page you arrive at: flush first, everything else second.
Begin flushing immediately with clean running water or saline. Every second counts.
Hold the eyelid open with your fingers if the person cannot keep it open voluntarily
Flush continuously for at least 15–20 minutes — use a large volume of water. More is better.
Remove contact lenses only if they come out easily during flushing — do not delay irrigation to search for them
Call 911 or seek emergency medical care after flushing. Identify the chemical if possible — the container label helps determine appropriate treatment.
Alkali burns are worse than acid burns
Alkaline chemicals (lye, drain cleaners, cement, ammonia) cause more severe and rapidly progressive eye injury than most acids. Acids typically cause an immediate surface burn that limits further penetration. Alkalis continue to penetrate and destroy tissue even after the chemical has been removed. For alkali exposures, err toward the longer end of the flushing window — 30 minutes or more if possible.
Do not attempt to neutralize one chemical with another (e.g., using a base to counteract an acid) — this can create an exothermic reaction in the eye. Use water only.
The saline eye wash bottle
A small sterile saline eye wash bottle ($6–$12 at any pharmacy) in your first-aid kit provides a much more controlled, comfortable flush than a running tap — especially in a field setting. It's one of the highest-value small additions to any kit that includes chemical exposure risk: workshop, garden, laboratory, or outdoor use.
Hyperventilation
Hyperventilation is rapid, shallow breathing that exhales carbon dioxide faster than the body can produce it. The resulting drop in CO₂ causes the symptoms: tingling in the hands, feet, and lips; dizziness; chest tightness; a strange feeling of unreality; and, paradoxically, a sensation of not being able to get enough air — despite breathing rapidly.
It is most commonly triggered by panic, fear, emotional distress, or acute pain. It can also be a symptom of asthma, heart problems, pulmonary embolism, low blood sugar, or other serious conditions. This is the key complication: what looks like hyperventilation from anxiety can sometimes be a medical emergency. The response must account for that possibility.
Speak calmly and quietly
Your tone is the first intervention. Lower your voice. Speak slowly. The person's nervous system is registering alarm — a measured, unhurried presence begins to interrupt that signal. Urgency in your voice makes hyperventilation worse.
Move away from crowds or stressors if possible
Being surrounded by concerned onlookers amplifies the stress response. Guide the person to a quieter, less crowded space. Sit beside them rather than hovering over them.
Coach controlled breathing
Guide the person to breathe in slowly through the nose to a count of four, pause briefly, then exhale slowly through pursed lips to a count of six or eight. Slowing the exhale is more effective than trying to slow the inhale. Model the breathing yourself — breathe with them.
Keep talking to them throughout
Simple, calm narration — "good, breathe out slowly, you're doing well, keep going" — keeps the person focused and provides a steady external rhythm to follow. It also prevents them from spiraling further into the fear that they can't breathe.
The paper bag method — why it's no longer recommended
The old advice to breathe into a paper bag aimed to increase CO₂ by rebreathing exhaled air. The problem: symptoms that look exactly like hyperventilation from anxiety can also be caused by asthma, pulmonary embolism, cardiac events, diabetic ketoacidosis, or other conditions where reducing oxygen intake is dangerous or even fatal. Without knowing the cause, the paper bag creates risk. Controlled breathing coaching achieves the same goal safely.
Call 911 if any of these are present
Panic attack vs. cardiac event
The distinction between a panic attack and a cardiac event can be genuinely difficult in the moment. Both can produce chest tightness, shortness of breath, dizziness, and the sensation of impending doom. Chest pain that radiates to the arm, jaw, or back, pain out of proportion to the apparent stress level, or symptoms in someone with known cardiac risk factors warrant 911 regardless of how the presentation initially looks.
When in doubt, call.
Nosebleeds
Most nosebleeds come from the front of the nasal septum — a small area rich in blood vessels. They look alarming but stop with sustained pressure in the vast majority of cases. The most common first-aid mistake is tilting the head back, which directs blood down the throat — causing nausea, vomiting, and aspiration risk. Lean forward.
Have the person sit upright and lean slightly forward — not backward
Pinch the soft part of the nose firmly — closing both nostrils. The soft part is below the bony bridge.
Have the person breathe through the mouth while holding pressure
Maintain continuous pressure for 10 to 15 minutes without releasing to check. Releasing early is the other most common mistake.
After bleeding stops: avoid nose blowing, picking, bending over, or heavy exertion for at least several hours
When to seek care
The two common mistakes
Tilting the head back
Directs blood toward the throat rather than out. The person swallows blood, which can cause nausea and vomiting — and in significant quantities, aspiration. Always forward.
Releasing pressure too soon
Lifting fingers every two minutes to check whether it's stopped restarts the clotting process each time. Hold for the full 10–15 minutes before checking. Set a timer if necessary.
Posterior nosebleeds
Most nosebleeds originate at the front of the nasal septum (anterior) and respond well to pinching. A small percentage originate deeper in the nasal cavity (posterior) — these tend to be heavier, don't respond to simple pressure, and require medical intervention. If the blood flow is heavy, appears to come equally from both sides of the nose, or runs down the throat despite leaning forward, seek medical care promptly.
Blisters & hot spots
A blister forms when friction, pressure, heat, or rubbing separates the layers of skin and fluid fills the space. On feet, this typically happens during hiking, walking long distances, breaking in new footwear, or switching to different shoes for an outing. A hot spot — the precursor — is the window of opportunity.
The earlier you act, the smaller the problem. A hot spot addressed immediately stays a minor irritation. Ignored through the next three miles, it becomes a large, painful blister that limits your day.
Hot spots: act immediately
A hot spot is a tender, warm, pink area where a blister is beginning to form. The skin is still intact. You have a short window to intervene.
Stop and remove the shoe or boot immediately. The longer you wait, the worse it becomes.
Dry the area thoroughly if possible — moisture accelerates blister formation.
Cover with moleskin, molefoam, or a blister bandage cut larger than the tender area — the padding should extend well beyond the hot spot edges.
Address the friction source before continuing — a loose sock, a seam, a shoe that rubs at a specific point. Fixing the cause matters as much as treating the hot spot.
Formed blisters: protect, don't pop
A blister that has already formed is the body's own sterile dressing. Leaving it intact protects the raw tissue underneath and dramatically reduces infection risk.
Cover loosely with a non-stick bandage or use donut-shaped padding (cut a hole in the center of the moleskin) to eliminate pressure on the blister without bursting it
If a blister opens on its own, do not remove the overlying skin if it is still loosely attached — it continues to protect the wound. Clean gently, leave the skin flap in place, apply a clean dressing, and watch for infection.
Change the dressing daily and check for infection — increasing redness, warmth, pus, or red streaks from the site
Draining a large blister — when it's warranted and how to do it safely
If a blister is very large, extremely painful, and likely to rupture with the next step anyway — it can be carefully drained using clean technique. Do not drain blisters on people with diabetes, poor circulation, immune compromise, or any sign of infection. Those blisters warrant medical advice.
Wash your hands thoroughly with soap and water
Clean the blister surface with soap and water or an antiseptic wipe
Wipe a fine needle with a fresh antiseptic wipe — do not use a match to sterilize it (leaves carbon residue)
Pierce the edge of the blister (not the center) with the needle, making a small hole
Allow fluid to drain gently — do not squeeze the blister forcefully
Leave the overlying skin in place — it protects the wound. Apply a clean non-stick dressing.
Blister prevention
Moleskin and molefoam — the foundation of foot first aid. Carry several pre-cut pieces in your kit. Apply at the first sign of rubbing, not after the blister forms.
Blister bandages (hydrocolloid dressings like Band-Aid Blister, Compeed) — gel-filled cushions that absorb impact, reduce friction, and can stay on for several days. More protective than standard bandages for formed blisters.
Wool or moisture-wicking synthetic socks — cotton holds moisture against the skin and accelerates blister formation. The single biggest footwear change for blister prevention on hikes.
Liner socks — thin sock liners worn under heavier hiking socks transfer friction to the sock-on-sock interface rather than sock-on-skin. Effective for people prone to blisters despite proper footwear.
Breaking in footwear
Most trail-related blisters come from wearing new or stiff footwear on the first long outing. Break in hiking boots and trail shoes with progressively longer walks before the trip they're intended for — not on the trip itself. New shoes should have at least 10–15 miles of gradual wear before any hike over 5 miles.
Fainting
Fainting (syncope) is a brief, temporary loss of consciousness caused by a sudden drop in blood flow to the brain. The person loses muscle tone and falls. Most fainting episodes are benign — caused by standing too long, heat, dehydration, standing up too quickly, seeing blood, or emotional distress. Recovery is typically rapid and complete.
The injury risk is in the fall. A person who loses consciousness while standing falls with their full body weight and no protective reflexes. The first job of a bystander who recognizes pre-faint warning signs is to prevent that fall.
Warning signs someone is about to faint
Sudden paleness of the face and lips
Clamminess or cold sweating
Dizziness or lightheadedness
Nausea and a weak feeling in the legs
Vision narrowing or tunneling
"I feel like I'm going to pass out"
Get them down before they fall
If someone reports feeling faint, immediately help them lie down on their back or sit with their head between their knees. Do not let them remain standing. A controlled lowering to the floor is far better than a sudden fall.
Elevate the legs if possible
Raising the legs above heart level encourages venous return — blood flows back from the lower extremities toward the heart and brain. A rolled jacket under both ankles works. This is one of the most effective immediate interventions for simple fainting.
If they've already fallen — check for injury first
Before focusing on the fainting itself, check for injuries from the fall — head, wrist, hip. A person who fell straight down and struck their head may have sustained a head injury that needs evaluation regardless of the fainting cause. If head or spine injury is possible, take spinal precautions.
Keep them lying down for several minutes after recovery
The natural impulse after regaining consciousness is to sit or stand up immediately. This often causes a second episode. Keep the person lying down for at least 3–5 minutes after full recovery, then sit them up slowly before standing.
Offer water once fully conscious and free of nausea
If dehydration or heat may have contributed, small sips of cool water once the person is alert help. Do not give fluids while they're still disoriented.
Call 911 or seek same-day medical care when:
Doesn't regain consciousness within 1–2 minutes
First fainting episode — always warrants evaluation
Associated with chest pain or palpitations
Person is pregnant
Person has diabetes, heart disease, or is elderly
Injured in the fall — any head impact especially
Common causes and prevention
Prolonged standing or sitting in heat
Blood pools in the legs. Military personnel, people standing in long lines, spectators at outdoor events. Shifting weight, walking in place, or sitting down breaks the pooling cycle.
Orthostatic hypotension
Fainting when standing up quickly. Blood pressure temporarily fails to keep up with the postural change. Common in older adults, those who are dehydrated, or people on certain blood pressure medications. Stand up slowly; pause at the sitting position first.
Vasovagal syncope
The most common type — triggered by seeing blood, sudden emotional shock, pain, or fear. The vagus nerve causes a sudden drop in heart rate and blood pressure. Recovery is typically rapid when lying flat.
Dehydration and heat
Inadequate fluid volume reduces blood pressure under stress. Prevention: stay hydrated before events involving prolonged standing in heat.
Diabetic emergencies
Diabetic emergencies are more common in the community than most people realize — and the most frequent is low blood sugar (hypoglycemia). The symptoms can look almost exactly like alcohol intoxication: confusion, slurred speech, unsteady gait, aggression, or unresponsiveness. A person in diabetic shock is sometimes ignored, avoided, or even arrested before someone recognizes what's actually happening.
The distinguishing question: does this person have diabetes? A medical ID bracelet, a medical ID phone screen, or asking the person directly are all fast ways to check. If the answer might be yes, treat for low blood sugar first.
Low blood sugar (hypoglycemia) — the common emergency
Signs:
Shakiness, trembling
Sweating and pale skin
Rapid heartbeat
Headache and irritability
Confusion, slurred speech
Unsteady movement — looks "drunk"
If conscious and able to swallow — give sugar immediately
Give 15–20 grams of fast-acting carbohydrate: 4 oz (half a cup) of fruit juice or regular soda, 3–4 glucose tablets, a tablespoon of sugar in water, or glucose gel if available. These options raise blood sugar within 15 minutes.
Wait 15 minutes and check the response
If symptoms are improving after 15 minutes, have the person eat a small snack with protein and complex carbohydrate (crackers with peanut butter, cheese and crackers) to stabilize blood sugar over the next hour. If symptoms are not improving, give another 15–20g of fast sugar and call 911 if still no improvement.
If unconscious or unable to swallow — call 911, give nothing by mouth
Do not give food or drink to an unconscious person or anyone who cannot swallow safely — aspiration risk. Place them in the recovery position if breathing, begin CPR if not. Call 911. If glucagon is available and you know how to use it, administer per the device instructions.
The key distinction
If you suspect low blood sugar in a conscious person who can swallow, giving sugar is safe even if you're wrong. If their blood sugar is actually high (hyperglycemia), a small amount of sugar will not cause immediate serious harm. But if their blood sugar is low and you don't act, they can lose consciousness rapidly.
The risk of giving sugar unnecessarily is negligible. The risk of not giving it when needed is severe. Err toward treatment.
High blood sugar (hyperglycemia)
High blood sugar develops over hours, not minutes. Symptoms include excessive thirst, frequent urination, blurred vision, headache, nausea, and fatigue. It rarely causes a sudden street emergency the way hypoglycemia does.
If a known diabetic person is ill, not improving, and you're unsure whether blood sugar is high or low — call 911. Don't attempt to guess treatment for hyperglycemia without medical guidance.
For households with a diabetic member
Continue reading
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What to do when someone is pulled from water, secondary drowning awareness, and the recovery position for an unconscious but breathing person.
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