Heat Exhaustion, Sunburn and Vacation Illness in Hawaii

The danger in Hawaii is that you do not feel it coming. The trade winds dry your sweat and the ocean keeps your skin cool, so you overheat and burn before your body sends the usual warnings. The one rule that keeps a bad day from becoming an emergency is simple. If someone in the heat becomes confused, collapses, stops making sense, has a seizure, or cannot stop vomiting, call 911 now and start cooling them, and do not wait to see if it passes or put them in a hot car to drive to the ER. Everything else in this guide is how to handle sunburn, heat exhaustion, and getting sick before it ever gets to that point.

Last updated 6 July 2026. This is general information for travelers, not medical advice, and it cannot diagnose your condition. In an emergency call 911. When in doubt, get seen. Children, older adults, pregnant travelers, and people with heart, kidney, or immune conditions should seek care earlier than the general thresholds below.

When it is an emergency

Call 911 now, then start cooling, if the person is:

Confused, slurring words, not making sense, unconscious, or having a seizure
Burning hot in the heat, whether the skin is dry or still sweating
Having trouble breathing, or has swelling of the face, tongue, or throat after eating fish
Fainting, with a racing weak pulse, and not passing urine

Go to the ER or urgent care today if you: cannot keep any fluids down for several hours, have a high fever, have a badly blistering sunburn and feel unwell, have numbness or a hot-and-cold feeling reversal after eating reef fish, or are simply getting worse. A young child with a high fever, constant vomiting, no wet diapers, or unusual sleepiness should be seen promptly.

You can usually manage it in your room if you are: awake and clear-headed, able to hold down small sips, and slowly improving. This guide tells you how, and when that changes. If you are unsure, it is fine to call the front desk or a nurse line. In Hawaii, emergency is 911, and Poison Help is 1-800-222-1222.

Key takeaways

The line between heat exhaustion and heat stroke is mental state. Confused, slurring, or passing out means heat stroke, which is a 911 emergency.
In Hawaii you can overheat and burn without feeling hot, because the wind and ocean hide the warning signs.
Cooling the body matters more than drinking water in a heat emergency, and you should never force fluids into someone confused or vomiting.
Hawaii’s sun is extreme. Unprotected skin can burn in as little as 10 to 15 minutes, and a beach umbrella does not fully protect you.
If you get sick from food or water, the realistic path to any money back is travel insurance, not a hotel refund, and it depends on documents you can only gather while you are still on the island and still sick.

In this guide

Heat exhaustion vs heat stroke symptoms and what to do
Why Hawaii burns you faster than the mainland
Treating a bad sunburn and sun poisoning
Dehydration and how to tell it is serious
Norovirus and the resort stomach bug
Food poisoning and reef-fish illness
Getting seen and getting reimbursed
Frequently asked questions

Heat exhaustion vs heat stroke symptoms and what to do

The dividing line is mental state. If the person is confused, slurring, unconscious, or seizing during heat or sun, treat it as heat stroke and call 911, and do not wait for a thermometer. Heat exhaustion is serious but the person stays alert and makes sense. This one distinction decides everything.

Sign	Heat exhaustion (serious)	Heat stroke (call 911 now)
Mental state	Alert, may feel dizzy or irritable	Confused, slurred speech, passing out, seizures
Body temperature	Elevated, generally up to 104°F (40°C)	Above 104°F (40°C)
Skin	Heavy sweating, cool or clammy	Hot, and may be dry or still sweating. Sweating does not rule it out
Other signs	Headache, nausea, weakness, thirst, less urine	Rapid pulse, throbbing headache, collapse
What to do	Cool down, sip water, rest. See a doctor if no better in 30 to 60 minutes or getting worse	Call 911, cool aggressively with ice to the neck, armpits, and groin, stay with them

The 104°F figure comes from clinical guidance such as the Mayo Clinic, but you cannot measure someone’s core temperature on a beach, so never use “it is probably under 104” to rule out heat stroke or to delay a 911 call. Judge it by how the person is acting, not by a forehead thermometer.

For heat stroke, which is any of the confused, collapsed, seizing, or burning-hot signs, call 911 first, then start cooling immediately while you wait. Move the person into shade or air conditioning, take off outer clothing, and put ice or cold wet cloths on the neck, armpits, and groin, or get them into cool water. Cooling matters more than drinking, and you must not pour fluids into someone who is confused or vomiting, because it can go into their lungs. Heat stroke is never something to manage in a hotel room.

For heat exhaustion, where the person is fully alert, get them to a cool place, have them sip cool water, remove extra clothing, and cool the skin with cold cloths. It should ease within about 30 to 60 minutes. That 30-to-60-minute guidance applies only to heat exhaustion in someone who is alert. If they are not improving, or get worse at any point, or their thinking changes, treat it as an emergency and call 911.

Why Hawaii burns you faster than the mainland

Hawaii’s UV Index routinely runs 10 to 11 or higher, the EPA’s “Extreme” category, because the islands sit at a tropical latitude where the sun is nearly overhead year-round. At those levels the EPA warns that unprotected skin and eyes can burn in minutes, for some people in as little as 10 to 15 minutes. Even a clear winter day here delivers a large share of summer’s UV. Cloud does not save you either, because most UV passes straight through light cloud.

The Hawaii trap is that you do not feel it happening. The trade winds evaporate your sweat before you notice it, and water in the 70s and 80s feels refreshing, so the heat and thirst cues your body normally uses are muted while your skin cooks and your core temperature climbs. By the time you feel cooked, you already are. Sand and water also bounce extra UV up onto you, which is why a beach umbrella alone does not fully protect you and why snorkelers so often burn the backs of their legs and necks. Cover up with a rash guard, wear a hat and UV sunglasses, seek shade between 10am and 4pm, and use a broad-spectrum SPF 30 or higher, reapplied every two hours and after swimming or sweating. On which sunscreen to buy, and Hawaii’s ban on two reef-harming chemicals, see our guide to Hawaii’s sunscreen law.

Treating a bad sunburn and sun poisoning

For an ordinary bad sunburn, cool the skin with frequent cool showers or baths, apply aloe vera or a light moisturizer while the skin is still damp, take ibuprofen or acetaminophen for the pain and swelling, and drink extra water, because a burn pulls fluid to the skin and dries you out. If blisters form, leave them alone. Blisters are a second-degree burn and the skin over them protects against infection, so do not pop them. Skip the folk remedies too, because butter, vinegar, toothpaste, and numbing sprays that end in “-caine” can irritate the skin or cause a reaction.

Sun poisoning is the name for a severe sunburn reaction that makes you feel genuinely sick, and it needs medical attention. Get seen for a sunburn if you have a high fever, chills, or nausea, if blisters cover a large area or are on the face or genitals, if a burn shows signs of infection like pus or spreading redness, or if you feel confused, faint, or have eye pain or vision changes. A significantly sunburned infant or young child should be seen. A mild burn settles in a few days, while a blistering one can take one to two weeks or longer. One thing many visitors miss: some common medications, including certain antibiotics like doxycycline and some acne and blood-pressure drugs, make you burn much faster, so check your prescriptions before a beach day.

Dehydration and how to tell it is serious

Heat, activity, and alcohol together dry you out fast in Hawaii, and alcohol makes heat illness worse, which is why a day of midday sun, exertion, and drinks by the water is the classic setup for trouble. You can check yourself with three questions. Are you still passing urine, and is it pale rather than dark? Do you feel dizzy or lightheaded when you stand up? Is your heart racing? Dark or absent urine, dizziness on standing, a fast pulse, headache, and cramps all point to dehydration. Drink water or an electrolyte drink, get into the shade, and rest. Severe dehydration can drop your blood pressure dangerously, so if you are fainting, cannot keep fluids down, or feel your heart pounding, get seen, because you may need fluids through an IV.

Norovirus and the resort stomach bug

The fast-moving stomach bug that sweeps through resorts and tour groups is usually norovirus. It brings sudden vomiting and watery, non-bloody diarrhea with cramps and sometimes a low fever, it typically starts 12 to 48 hours after you are exposed, and most people are better within one to three days. Here is a useful clue: if everyone who shared the same meal or the same space gets sick around the same time, that points to a shared source rather than a coincidence.

The main danger is dehydration, so the job is to keep fluids in. When you cannot stop vomiting, do not try to gulp a glass of water. Take small sips or ice chips every few minutes, and step up to more as it stays down. Rest, and stay out of shared pools, hot tubs, and buffets, because norovirus spreads easily and you can pass it for two weeks or more after you feel better. Wash your hands with soap and water, because hand sanitizer does not work well against norovirus. Get medical help if you cannot keep any fluids down, if there is blood in the stool, a high fever, confusion, or clear signs of dehydration, and sooner for young children, older adults, and anyone with a chronic illness.

Food poisoning and reef-fish illness

Ordinary food poisoning behaves much like norovirus, with vomiting, diarrhea, and cramps that you manage by resting and keeping fluids down, and that you get seen for if there is bloody diarrhea, a high fever, severe dehydration, or you simply are not improving. Two fish-related illnesses in Hawaii deserve their own mention because they behave differently.

Ciguatera comes from a toxin that builds up in certain reef fish, and it is the one that surprises people, because the toxin has no taste or smell and cooking, freezing, drying, and salting do not destroy it. On top of the usual stomach upset it causes nerve symptoms, most tellingly a reversal of hot and cold so that cold water feels burning, plus tingling or numbness around the mouth, hands, and feet, itching, a metallic taste, and sometimes a slow heartbeat. Symptoms can start within a few minutes to several hours. There is no cure, only supportive care from a doctor, and the nerve effects can linger for weeks or months, so avoiding fish, nuts, alcohol, and caffeine for a while lowers the chance of a flare-up. Higher-risk fish include barracuda, moray eel, grouper, amberjack, snapper, and the local papio and kahala, and you should avoid the head, guts, liver, and roe of reef fish. See a doctor for the nerve symptoms, and note that ciguatera is a reportable illness in Hawaii. A clinician can report it, and the state Department of Health disease reporting line is (808) 586-4586.

Scombroid comes from fish, often tuna, mahi-mahi, mackerel, or marlin, that was not kept cold enough, and it looks like an allergic reaction, with flushing, headache, a pounding heart, itching, and cramps starting within an hour of eating. A doctor typically treats it with antihistamines and it usually passes in a day or two. But if it causes trouble breathing, wheezing, or swelling of the tongue, throat, or face, that is a life-threatening reaction. Call 911, because that needs epinephrine, not another antihistamine at home.

Getting seen and getting reimbursed

Most visitors who get sick do not get a refund from the hotel, so it helps to be realistic about what actually works, and to gather the right evidence before you leave the island. The single most important thing is this: if you think the food or water made you sick, get a stool test and a signed note from a doctor now, while you are still on the island and still sick, and write down exactly when you ate what and when your symptoms started. A doctor’s note proves you were sick, but a lab test that names the germ, collected within a few days before it clears, plus that eat-time-versus-symptom timeline, is what actually connects your illness to a source. Once you have recovered and flown home, that evidence is gone.

If a restaurant, resort, or luau meal is the likely cause, our full guide to food poisoning in Hawaii and how to get money back covers proving it, reporting it to the health department, and the refund, insurance, and claim options in detail.

From there, the realistic ladder runs like this.

Tell the hotel now and ask, politely, for a refund or credit. Get it logged in their records. Many hotels will comp a night as goodwill for a clear case, especially if other guests are sick too, and every later step builds on that report.
Travel insurance is the most realistic path to actual money, if you bought a policy and were genuinely sick. Trip interruption can repay the unused, prepaid, non-refundable part of your trip when a doctor certifies you were unable to continue, and travel medical can cover treatment costs, which matters in Hawaii because visitor ER and urgent-care bills are often out of network. A mild one-day bug usually will not qualify. You generally must notify the insurer within about 72 hours and file within about 90 days, and you will need the doctor to complete an attending physician statement, so get that signed on-island. Our guide to travel insurance for Hawaii covers what is and is not covered, and what an ER or urgent care visit costs a visitor.
A credit card chargeback is the fallback if the hotel refuses a fair refund request. Ask the hotel in writing first, then dispute the charge with your card issuer. This works more cleanly for a room you could not use than for an illness alone. Our guide to disputing a hotel charge covers the process.
A state consumer complaint to Hawaii’s Office of Consumer Protection creates a record and some pressure, but it does not recover your money and does not handle billing disputes.
Small claims court is an option for a documented, meaningful loss, with a limit of $5,000, though as a mainland visitor you would generally need to attend or arrange to appear, as our guide to small claims court in Hawaii explains. A room-condition refund, such as the parallel with an uninhabitable room, is usually a stronger case than illness.
Walk away. For a mild bug with no test and no outbreak, this is the honest default. The effort to chase it will exceed anything you realistically recover.

This part is general information about consumer options, not legal, financial, or insurance advice. Whether you are covered or owed anything depends on your specific policy and circumstances, so check your policy and ask the relevant company.

Frequently asked questions

What is the difference between heat exhaustion and heat stroke?

The dividing line is mental state. In heat exhaustion the person stays alert and makes sense, with heavy sweating, headache, nausea, and weakness. In heat stroke the brain is affected, so the person becomes confused, slurs their speech, passes out, or has a seizure, usually with a very high body temperature. Heat stroke is a life-threatening emergency. Call 911 and start cooling immediately.

What are the warning signs of heat stroke?

Confusion, slurred speech, loss of consciousness, or seizures during heat or sun exposure, along with a very high body temperature and skin that is hot to the touch, whether dry or still sweating. Do not assume it is not heat stroke just because the person is sweating. Any of these signs means call 911 now, move them to a cool place, and put ice on the neck, armpits, and groin.

Can you get heat exhaustion without feeling hot in Hawaii?

Yes. In Hawaii the trade winds evaporate your sweat before you notice it and the ocean keeps your skin cool, so the usual heat and thirst warnings are muted while your core temperature still climbs. You can be overheating and burning without feeling hot. By the time you feel cooked, you already are, which is why drinking water and taking shade breaks before you feel bad matters so much here.

When should I go to the ER for heat illness or sunburn in Hawaii?

Call 911 for any sign of heat stroke, which is confusion, collapse, seizures, or a burning-hot person. Go to the ER or urgent care for heat exhaustion that does not improve within 30 to 60 minutes of cooling, a sunburn with high fever or extensive blistering, an inability to keep fluids down, or signs of serious dehydration. When in doubt, get seen, and do not let the cost of care stop you from an emergency.

How long does heat exhaustion last?

Heat exhaustion should ease within about 30 to 60 minutes of cooling down, resting, and sipping fluids. If it does not improve in that time, or gets worse, or the person becomes confused, treat it as heat stroke and call 911. Full recovery and feeling normal again can take a day or so, during which you should avoid heat and keep hydrating.

How fast can you get sunburned in Hawaii?

Fast. Hawaii’s UV Index routinely reaches the Extreme range, and unprotected skin can burn in as little as 10 to 15 minutes at midday. It burns faster than most of the mainland because the islands sit at a tropical latitude with near-overhead sun year-round, and because sand and water reflect extra UV onto you.

Does a beach umbrella protect you from sunburn?

Not fully. Sand and water reflect UV up and around, so you can burn in the shade of an umbrella, especially on the backs of your legs, your neck, and your face. An umbrella helps, but you still need sunscreen, and covering up with a rash guard and hat is more reliable than shade alone.

What is sun poisoning and how is it different from sunburn?

Sun poisoning is a severe sunburn reaction that makes you feel genuinely ill, with fever, chills, nausea, extensive blistering, or feeling faint, rather than just red and sore skin. An ordinary sunburn is treated at home, but sun poisoning warrants medical attention, and any confusion, fainting, or vision changes with a bad burn should be seen urgently.

What should I put on a bad sunburn, and what should I avoid?

Cool the skin with cool showers, apply aloe or a light moisturizer while damp, take ibuprofen or acetaminophen, and drink extra water. Leave any blisters intact, since popping them invites infection. Avoid butter, vinegar, toothpaste, and numbing sprays ending in “-caine,” which can irritate the skin. See a doctor if there is fever, infection, or large or facial blisters.

Is it food poisoning or norovirus, and how can I tell?

You often cannot tell them apart at home, and the treatment is the same: rest, small sips of fluids, and watching for dehydration. A clue is timing and spread. Norovirus usually starts 12 to 48 hours after exposure and races through groups, while some food poisoning hits within hours of a specific meal. If everyone who ate the same thing got sick together, that points to the food. Either way, seek care for bloody diarrhea, high fever, or fluids you cannot keep down.

Can you get sick from eating reef fish in Hawaii?

Yes. Ciguatera is a toxin in certain reef fish, such as barracuda, grouper, amberjack, papio, and kahala, that cooking cannot destroy and that causes stomach upset plus nerve symptoms like tingling and a reversal of hot and cold. There is no cure, only supportive care, so see a doctor for the nerve symptoms. Scombroid, from fish that was not kept cold, causes an allergic-type reaction treated with antihistamines, but any breathing trouble or throat swelling is a 911 emergency.

Can I get a refund if I got sick at my Hawaii hotel?

A hotel refund is possible but unlikely, and usually offered as goodwill rather than admitted liability. The more realistic path to money back is travel insurance, if you were insured and genuinely sick enough to interrupt your trip or need care. Whatever route you take depends on evidence you can only gather now: a stool test naming the germ, a signed doctor’s note, and a written timeline of what you ate and when symptoms began. Report it to the hotel immediately and get seen while you are still on the island.

Related guides

Sources include the CDC, the Mayo Clinic, the American Academy of Dermatology, the EPA, and the Hawaii Department of Health. This is general information, not medical advice. When in doubt, get seen.