Public health advice in the aftermath of flooding: how to protect your health and keep safe

The following actions can help you prevent or minimize direct health consequences from flooding:

• After a flood, avoid walking or driving through flood water or entering unstable buildings or structures. There may be hidden hazards, such as holes or fast-flowing water.
• If you are stranded on something above the flood water, such as a tree or building, wait there for rescue and do not enter the water.
• Only try to rescue pets or farm animals if it is safe to do so.
• Only return home if you have been advised that it is safe to do so.
• If you are injured or have a wound that can be contaminated, seek medical assistance. 

Always keep yourself informed by using official sources of information and follow guidance from your local authorities. If you are advised to evacuate your home, take your essential portable belongings and any medicines you might need in the short term in a waterproof bag. If requested not to evacuate, move to a safe location recommended by the local authorities with essential items.

Staying in water that is less than 20 °C for a long time can increase risks of hypothermia. Hypothermia happens when your body temperature drops below 35 °C.

Signs of hypothermia are: 

• shivering
• pale, cold and dry skin – skin and lips may be blue
• slurred speech
• weak pulse and slow breathing
• tiredness or confusion.

A baby with hypothermia may be:

• cold to touch and their skin may be red
• flaccid
• unusually quiet and sleepy and may refuse to feed.

First aid for hypothermia includes:

• moving the person indoors or somewhere sheltered and dry as quickly as possible, if it is safe to do so;
• removing any wet clothing, wrapping them in a blanket, sleeping bag or dry towel, and making sure their head is covered;
• giving them a warm non-alcoholic and caffeine-free drink and, if they are fully awake, some sugary food like chocolate; 
• keeping them awake by talking to them until help arrives; 
• making sure you or someone else stays with them.

After a flood, there is a risk of getting ill with diseases transmitted by rodents (such as leptospirosis) and mosquitoes (such as West Nile virus), as well as snake bites. If you or someone you know becomes ill, seek medical help.

You can protect yourself and your family by following the steps outlined below. 

Rodents

Rodents can be displaced from their normal habitat, like sewers, due to flooding and seek places where they can find food and shelter, such as in people’s homes. Rats’ droppings and urine can contaminate food and spread diseases. To prevent such risks:

• ensure that all entrances and windows are sealed to prevent entry of rodents into the property;
• cover skin lesions with waterproof dressings; 
• wear rubber boots, waterproof gloves, goggles and a face mask if you go into flood water, to avoid contamination from rodents or snake bites;
• keep your food in sealed cupboards and containers, in a dry place out of the reach of rodents;
• do not leave pet food out in the open;
• keep waste sealed in rubbish bins.

Mosquitoes

Emergencies such as flooding may lead to more mosquitoes, which can carry disease. If your home is in an area with stagnant or standing water, use mosquito repellent, following the instructions on the label, and apply it to clothes or skin.

Snake bites

Snake bites are also common during floods. Bites by venomous snakes can cause severe consequences. If a snake has bitten you, immediately seek medical help. If you are around someone who was bitten by a snake: 

• Seek medical help immediately. Antivenoms are the only effective treatment to prevent or reverse most of the venomous effects of snake bites.
• Calmly talk to the person, explain to them what is happening and what you are doing to help them; they might be very anxious.
• If you can, immobilize their body by lying them down in a comfortable and safe position and, especially, immobilize the bitten limb with a splint or sling.
• Do not touch, rub or massage, clean, or apply herbs or chemicals to the wound, as this may introduce infection, increase absorption of the venom and increase local bleeding.

Seek medical assistance if you:

• are injured; 
• are bitten by animals like rats or snakes; 
• have influenza-like symptoms, high fever, strong headache, heavy cough, strong diarrhoea and/or vomiting, or heavy dizziness;
• have heart pain;
• have a chronic disease and need your medication;
• have been exposed to chemicals or experience symptoms such as burning eyes, difficulty breathing or skin irritation.
• feel stressed and aggressive, have recurrent dreams of flooding and are worried about returning floods.

If you need to access a hospital:

• Check official information to find out which hospitals are functioning.
• Keep in mind that those with serious injuries and urgent needs will be prioritized.
• Let health-care workers know if you have any chronic medical conditions.

Floods can potentially increase the transmission of waterborne diseases, such as cholera or hepatitis. Making sure water is safe is not always easy after a flood, but it is essential to keep you and your family healthy.

• If you can, boil water before you use it for drinking, brushing teeth, cleaning wounds and food preparation to prevent the risk of waterborne diseases. After the water has reached a rolling boil, remove the pot or kettle from the heat and allow it to cool naturally. Do not add ice.
• Keep the hot water away from children to avoid scalding. Cool and store all boiled water in a clean and covered container. This protects the water from re-contamination.
• In case tap water or other local water sources are not available or safe, use bottled water if you can access it. Make sure that the bottled water you drink is properly sealed before you use it. Do not drink from the bottle if the seal is broken or twisted.
• Use tap water for other domestic purposes (e.g. cleaning, laundry) and personal hygiene (e.g. handwashing, bathing, showering), as it is safe to do so.
• Keep your hands clean. Handwashing with soap is important, especially before and during handling food and after going to the toilet. To be effective, wash your hands for 40–60 seconds with (un-boiled) water and soap, or 20–30 seconds with alcohol-based hand rub, if available.

After a flood, there is a risk of illness from eating food that is contaminated. Unsafe food and water can cause diarrhoea, vomiting, stomach cramps, fever, aches and fatigue, and can lead to serious illness. Making sure food is safe is not always easy after a flood, but it is essential to keep you and your family healthy.   

If possible, follow this advice to make sure your food is safe: 

• Separate raw and cooked food.
• Do not leave cooked food outside the refrigerator for more than 2 hours. Throw away perishable and cooked foods that have not been refrigerated properly due to power outages. 
• Plan when to eat different types of food – for example, eat perishable food first. 
• Avoid eating food that shows signs of spoilage or has come in contact with contaminated water.
• Keep clean and use boiled or bottled water for drinking and cooking, if possible. 

If there has been a power outage in your area, refrigerated or frozen food may not be safe to eat. After 4 hours of a power cut, the following apply. 

• Throw out all perishable foods in your fridge, such as meat, poultry, fish and leftovers. Products can become unsafe if they have been exposed to temperatures above 5 °C for more than 2 hours.
• Throw out all items in your freezer once they have thawed or cook them, if they have been exposed to ambient temperature for more than 2 hours. 
• Never eat food to determine if it is safe. If in doubt, throw it away. 

In case you are unable to store, cook or reheat your food properly, keep a stock of pre-packaged, tinned or ready-to-eat food, if possible. 

Handwashing with soap is important, especially before and during handling food and after going to the toilet. To be effective, you should wash your hands for 40–60 seconds with (un-boiled) water and soap, or 20–30 seconds with alcohol-based hand rub, if available.

People should avoid touching or handling dead animals, instead they should call the relevant local authorities to do so.

This includes not touching, collecting or eating dead fish. 

People working to clean up areas containing animal carcasses should wear protective clothing and observe basic hygiene, including:

• keeping hands clean to prevent infection with diseases that may be transmitted by farm animals;
• securing all food sources and removing animal carcasses to avoid attracting rats;
• wearing insect repellent when outdoors; emergencies such as natural disasters may lead to more mosquitoes, which can carry disease.

Do not return home until advised by local authorities. If you are advised that it is safe to return home, follow the guidance below:

• Never turn power on or off or use an electric appliance while standing in water.
• Have home gas and electrical appliances checked by qualified professionals before turning them on again.
• Leave doors and windows open whenever possible and safe, to dry out your home.
• Do not use petrol or diesel generators indoors. 
• Wear a face mask and rubber boots, waterproof gloves and an apron while cleaning.
• Keep children away from flood-contaminated and muddy areas until a week after the water has receded.

It is very important to get information, advice and guidance from official sources, such as your national and local health authority. 

An infodemic, with too much information including false or misleading information, can intensify during emergencies, cause confusion and lead to behaviours that can potentially harm health.  

Always check the source of information and analyse the content before taking action and sharing it with others.