Suspected Acute Radiation Syndrome: What to Do at Home While Getting Emergency Care

The most important point

Acute radiation syndrome (ARS), sometimes called radiation sickness, is a serious medical emergency. It cannot be diagnosed or treated at home. If you think you or someone nearby may have received a high radiation dose, follow emergency officials’ instructions, get inside and stay inside if authorities direct sheltering, and seek professional medical assessment as soon as officials say it is safe to do so. Contact local emergency services using the method officials recommend, explain the possible exposure, and follow the dispatcher’s directions. Do not leave shelter or drive to a hospital on your own during an active radiation emergency unless officials instruct you to, or there is an immediate life-threatening danger such as fire or an unsafe building.

The steps below are protective actions while help and official instructions are being arranged. They can reduce radioactive material on the body and limit its spread. They do not reverse radiation already absorbed by the body and do not treat ARS. See the CDC’s ARS guidance and follow local emergency alerts.

Quick summary

• Get inside, stay inside, and stay tuned to emergency officials.
• Report a suspected exposure or symptoms and ask where to get screened or treated. Seek medical care as soon as officials say it is safe.
• If you were outside, carefully remove your outer clothing and wash exposed skin and hair when safely inside. This is decontamination, not ARS treatment.
• Do not take potassium iodide (KI), supplements, or other medicines for a radiation event unless public health or emergency officials or a healthcare professional tell you to.

What you need

Estimated time: Start protective actions immediately. Decontamination time varies; do not delay contacting emergency services or care for a life-threatening injury to complete a shower.

Difficulty: Basic steps, but the situation is an emergency and requires professional guidance.

Emergency steps

Step 1: Treat a possible exposure as urgent, not as a home diagnosis

ARS occurs after a very high dose of penetrating radiation reaches most or all of the body over a short period. Symptoms alone cannot confirm it. Early symptoms may include nausea, vomiting, headache, and diarrhea. They can begin within minutes to days, may last for minutes or several days, and can come and go. A person may appear to feel better for a time before becoming ill again. Do not use a symptom-free period as proof that everything is safe.

If there has been a radiation emergency, possible high-dose exposure, or symptoms after a suspected exposure, tell emergency responders or public health officials what happened and follow their instructions about screening and medical care. Share when and where the exposure may have occurred, how long you were there, when symptoms started, and any changes. These details help professionals assess the situation; they do not let a person calculate or rule out ARS at home. Radiation itself cannot be reliably detected by sight, smell, taste, or touch.

If the person is unconscious, having a seizure, struggling to breathe, severely injured, or rapidly getting worse, communicate this immediately to emergency services and follow their instructions. Do not delay urgent care to wash. In an incident where contamination is possible, tell responders about it so they can use their established procedures.

Step 2: Get to a safe building and shelter

If you are outside, enter the nearest building as soon as you can. If you are already inside, stay there. During an official shelter-in-place instruction, go to a basement or the middle of the building, away from outside walls, doors, windows, and the roof. Close and lock windows and doors. If possible, turn off fans, air conditioners, and forced-air heating that bring outdoor air inside, and close fireplace dampers.

Stay indoors until emergency officials say it is safe to leave. CDC advises that sheltering for at least 24 hours can protect people while radioactive material weakens, but the right duration depends on the incident; follow current local instructions rather than relying on a fixed timer. Do not go outside to find relatives, KI, food, or clothing if officials have told people to shelter. Use official radio, television, phone alerts, or other channels to get updates.

Step 3: Reduce contamination on clothing and skin when safely inside

Being exposed to radiation and being contaminated are different. Exposure means radiation energy reached the body; contamination means radioactive material is on or inside it. Removing clothing and washing can reduce external contamination, but cannot undo a radiation dose that has already been absorbed. The CDC self-decontamination guide explains these steps.

1. Remove the outer layer carefully if you were outside. Avoid shaking clothing, which could release dust. Taking off the outer layer can remove up to 90% of radioactive material from the body. Put the clothing in a plastic bag or another sealable container, then place it away from other people and pets. Keep it there until authorities tell you how to handle it.
2. Wash exposed skin and hair gently. If you can shower, use warm water and plenty of soap. Do not use very hot water, scrub, or scratch your skin. Wash your hair with shampoo or soap. Cover cuts and scrapes while washing so material does not get into open wounds.
3. Use a simple alternative if there is no shower. At a sink, wash your hands, face, and exposed skin with soap and plenty of water. If you cannot use a sink, use a moist wipe, clean wet cloth, or damp paper towel. Pay attention to your hands and face; gently wipe your eyelids, eyelashes, ears, and nose. Put used wipes or cloths in a sealable bag and keep it away from people and pets.
4. Put on clean clothes if available. Do not leave shelter to get clothing. If supplies are limited, stay inside and wait for official guidance.

Decontamination is not a substitute for medical assessment. If you have a life-threatening condition, prioritize emergency care and follow the dispatcher’s instructions rather than delaying to shower.

Step 4: Do not self-prescribe radiation medicines

Do not take potassium iodide (KI) unless public health or emergency officials or a healthcare professional instruct you to. KI protects only the thyroid from radioactive iodine in certain situations; it does not protect the whole body from radiation or treat ARS. It can also cause harm when used incorrectly. Do not substitute table salt, iodine supplements, or other products for KI. See the CDC’s KI guidance.

ARS treatment is chosen by medical professionals after assessment. CDC describes clinical care as including infection prevention or treatment, hydration, and treatment of injuries and burns; some patients may need specific treatments to support bone marrow. Do not use someone else’s prescription, try to obtain radiation countermeasures without instructions, or take extra medicines to prevent a problem that has not been assessed.

Step 5: Keep following instructions and prepare for professional assessment

Remain in the designated shelter and monitor official messages. Keep a short record of the possible exposure time and place, your symptoms and when they began, any first aid or washing already done, and medicines you normally take. Share it with responders or clinicians. Do not handle suspected radioactive material or try to clean the building; officials will tell you whether a place or object needs special monitoring or cleanup.

If other people were outside, help them shelter without exposing yourself: ask them to remove outer clothing before entering when practical, then wash exposed skin and change into clean clothing if available. Keep children, older adults, pregnant people, and people who need assistance close to a responsible caregiver while following shelter instructions. Do not separate from a facility’s emergency plan to retrieve someone; schools, hospitals, care homes, and similar facilities have procedures for keeping people inside.

Troubleshooting

I cannot take a shower. What should I do?

Use a sink with soap and plenty of water to wash hands, face, and exposed skin. If there is no sink, use a moist wipe, clean wet cloth, or damp paper towel. Focus on hands and face, and bag the used materials. Do not go outside to look for supplies.

I have symptoms but officials have not said it is safe to leave.

Tell emergency services or public health officials about the symptoms and possible exposure using the available communication method. Follow their directions about urgent care and transport. Do not assume that nausea or vomiting proves ARS, but do not ignore symptoms after a radiation emergency or leave shelter without instructions.

Someone in my home may have brought radioactive dust inside.

Keep people and pets away from the clothing or item. Do not shake, sweep, or vacuum it. If the person was outside, follow the clothing and washing steps above. Ask emergency officials what to do next; responders will advise whether an area needs special cleanup.

Frequently asked questions

Can acute radiation syndrome be treated at home?

No. ARS is a serious illness that requires medical evaluation and professional treatment. Home steps can reduce external radioactive contamination and protect people while they wait for instructions; they cannot treat radiation absorbed by the body.

Does vomiting mean I have ARS?

No. Nausea and vomiting have many possible causes. ARS depends on the radiation dose, type of exposure, how much of the body was exposed, and timing. Only trained professionals can assess a possible exposure. After a radiation emergency, report symptoms and follow instructions for medical assessment.

Should I take KI after a suspected radiation exposure?

Only if public health or emergency officials or a healthcare professional tell you to. KI is useful only in particular circumstances involving radioactive iodine and does not treat ARS or protect the whole body.

Sources

• CDC: Acute Radiation Syndrome
• CDC: What to Do—Get Inside
• CDC: What to Do—Stay Inside
• CDC: How to Self-Decontaminate after a Radiation Emergency
• CDC: Potassium Iodide (KI)

This guide is general emergency information, not a diagnosis or treatment plan. Follow local emergency services and qualified health professionals.