A typical scenario (an illustrative situation, not the story of any particular shelter)

On the third night in the temple hall, coughing began from several corners at once

Pi Noi is a village health volunteer in a canal-side community on the eastern side of Bangkok. In late September 2026, according to news reports, around 300 millimetres of rain fell in roughly 48 hours, and on 26 September the Bangkok Metropolitan Administration declared all 50 districts a disaster zone. Water in Pi Noi's community rose so high that many single-storey houses became uninhabitable. About a hundred residents moved into the preaching hall of the nearby temple, which became a temporary shelter overnight.

On the first night everyone was simply relieved to be somewhere dry. Donated mats and blankets were laid out across the whole floor. Each family had two or three square metres. Older people slept right next to young children. The temple had only a few toilets, and they now had to serve a hundred people. Boxed meals were handed out by the entrance, and everyone took spoons, forks and cups from the same basket.

By the third night, Pi Noi noticed coughing coming from several corners at once. Many children had runny noses. One grandmother had a fever and was very tired. What made Pi Noi call for help immediately was an eight-month-old baby who was breathing fast, wheezing and feeding less. The district health team took the baby to a doctor that night. Later the mother said the doctor suspected a respiratory virus and wanted to monitor the baby closely.

The next morning Pi Noi looked around the hall and saw something she had never noticed before. The stair rail everyone held, the tap outside the toilets, the water scoops, the cutlery basket, the folding table where meals were set out: all of them were touched by a hundred pairs of hands, again and again, every day. Yet the only cleaning so far had been a sweep of the floor each morning.

Pi Noi's story is an illustration, but it reflects the reality of many shelters, whether in temples, schools, gymnasiums, community halls or district offices. This guide is written for shelter managers, volunteers, district staff, monks and temple committees, teachers whose schools have become evacuation points, and donors who want to know how to reduce the spread of influenza and RSV in crowded conditions. It sets out a hygiene plan that can actually be carried out and explains how surface disinfection with a medical-grade product such as Chemgene HLD4H fits into it.

Understanding influenza and RSV, and why they spread so easily in shelters

What is RSV?

RSV (respiratory syncytial virus) is a very common respiratory virus during Thailand's rainy season. In healthy adults it usually looks like a common cold, with a runny nose, cough, sore throat and mild fever. In babies and young children, especially those born prematurely or with heart or lung conditions, and in older adults, RSV can cause bronchiolitis or pneumonia, with fast or laboured breathing, wheezing and sometimes a need for hospital care.

Influenza

Influenza brings a sudden high fever, headache, muscle aches, cough and severe tiredness. People at higher risk of serious illness include older adults, young children, pregnant women, people with chronic conditions such as diabetes, heart disease or lung disease, and people with weakened immune systems.

How these viruses spread in crowded spaces

• Droplets from coughs and sneezes. When people sleep less than a metre apart, droplets from one person's cough can reach the next person directly.
• Surfaces and hands. Droplets land on rails, taps, tables and shared items, get onto the next person's hands, and then enter through the eyes, nose or mouth. According to general public health information, RSV can survive on hard surfaces for several hours.
• Poor ventilation. Halls and gyms closed up against the rain let droplets linger in the air for longer.
• Weakened bodies. Stress, lack of sleep, cold and damp, and incomplete meals all lower people's defences.

It is not only respiratory illness

Besides influenza and RSV, shelters face diarrhoeal illness from norovirus and bacteria in shared toilets, hand, foot and mouth disease among young children, skin infections and immersion foot from wading, and leptospirosis among people who wade back to check their homes. Anyone with high fever, calf pain or red eyes after wading needs to see a doctor immediately.

Danger signs that need a doctor right away

• A baby or young child breathing fast, with the ribs pulling in, wheezing, feeding or drinking poorly, or unusually drowsy.
• Bluish lips, fingers or toes.
• An older person with high fever, breathlessness, confusion or unable to get up.
• Severe diarrhoea with little urine and a dry mouth, signs of dehydration.
• High fever with calf pain after wading through floodwater.

Disinfectants reduce germs on surfaces; they do not treat illness. Anyone with symptoms should always be cared for by a doctor or the public health team.

What an outbreak in a shelter costs

The health of people who have already lost so much

Most evacuees have just lost their homes and belongings. Falling ill again in a shelter is a burden on body and mind. The most vulnerable, including babies, young children, older adults, bedridden people and pregnant women, may become sick enough to need hospital care.

The health system

During a flood, hospitals and public health centres are already stretched by injuries, chronic patients who have run out of medicine and difficult travel. Preventable outbreaks in shelters add to that load.

Families

When a child or older relative is admitted to hospital, family members must split up to care for them while still trying to restore their homes. Overlapping burdens delay the return to normal life even further.

Volunteers and shelter managers

Volunteers work long hours, sleep little and are in direct contact with people who are ill. If volunteers fall sick too, the shelter is left short-handed. A hygiene plan and the right supplies protect the people doing the work as well.

The buildings that open their doors

Temples, schools and community buildings have to return to normal use after the water recedes. Without cleaning and disinfection before the space is handed back, lingering germs could pass on to students, worshippers or the next group of users.

Why the usual efforts in shelters often fall short

1. Handing out masks without cleaning surfaces. Masks help a great deal for people who are coughing and sneezing, but germs that land on rails, taps and meal tables still travel by hand unless there is a routine for cleaning high-touch points.

2. Spraying disinfectant into the air or onto people. This should never be done. Spraying people, or misting a space while people are in it, does not reduce infection and can irritate eyes, skin and airways. Disinfectants are for surfaces only.

3. Using strong bleach in a closed hall. Harsh fumes in a space where older adults, young children and people with asthma are sleeping can worsen breathing problems, and bleach corrodes stainless rails, steel doors and aluminium fittings.

4. Cleaning once a day in the morning. Where hundreds share toilets and meal points, high-touch surfaces are recontaminated within hours. Several wipe-downs a day are needed.

5. Passing mats, cushions and blankets on without cleaning. When one family goes home and another moves in, the bedding may still carry germs from someone who was ill.

6. Not separating people with symptoms. When people with fever and cough sleep alongside babies and older adults, infection reaches the most vulnerable fastest.

7. Piling donations on the floor. Donated goods laid on damp or muddy floors and picked through by many hands become yet another shared touch point.

Chemgene HLD4H as part of a shelter hygiene plan

CHEMGENE HLD4H is a medical-grade high-level disinfectant made in England. According to the product information, it is used in hospitals, clinics, schools, airports and elderly-care and childcare settings: places where many people share the same space, just as they do in a shelter.

Product facts relevant to shelters

• The product information lists activity against influenza H1N1 and RSV, the two main concerns in crowded spaces during the rainy season, as well as norovirus, hand, foot and mouth disease virus, SARS-CoV-2, bacteria, Salmonella, fungi and mycobacteria.
• The product page states a 1-minute kill time and residual surface protection for up to 14 days.
• Dilutions of 1:30, 1:50, 1:60, 1:100 and up to 1:200 mean a given quantity can support several wipe-down rounds a day across a large area.
• It is non-corrosive to stainless steel, aluminium, rubber, plastic and fibreglass, so it can be used on stair rails, folding tables, plastic chairs, water buckets and scoops.
• The page states it is safe for people and pets when used as directed, and it is biodegradable.
• Listed tests and approvals include Mahidol University, NHS England, ISO 9001:2015, ISO 13485, SGS, Intertek, CE and EN 13727 / EN 14348 / EN 13624 / EN 14476.

Key rule: use Chemgene HLD4H on surfaces and objects only. Never spray it on people or mist it into the air above people who are sleeping. Wipe or spot-spray surfaces that have already been cleaned of visible dirt, wear gloves, and keep the space ventilated.

Divide the shelter into zones and set cleaning rounds

1. Registration and entrance. Set up a handwashing point or hand gel, and a place to leave muddy shoes. Wipe the registration table and pens several times a day.
2. Sleeping area. Lay mats with walkways between families and, where possible, have people sleep head-to-toe. Wipe floors and rails around the sleeping area daily, and clean plastic mats before passing them to a new family.
3. Toilets and bathing area. The highest-risk zone. Wipe taps, flush handles, door handles, scoops and bidet sprays with the stronger dilution on the label every two to three hours at busy times.
4. Food and drinking-water point. Servers wear gloves and masks. Use individually wrapped cutlery or give each family its own set. Wipe tables before and after every meal, rinsing food-contact surfaces with clean water as the label directs.
5. Children's and mother-and-baby corners. Use washable hard plastic toys, disinfect and rinse them daily, and avoid shared soft toys.
6. Symptom area. Set aside a space for people with fever, cough or diarrhoea, away from babies and older adults, with masks and hand gel ready. Wipe surfaces here more often and inform the health team.
7. Donation store. Keep goods on shelves or pallets off the floor, and have volunteers hand items out rather than letting everyone pick through them.
8. Before closing and handing back. Deep-clean the whole building: remove dirt, dry, then disinfect all surfaces with Chemgene HLD4H before returning the space to the temple, school or community.

Alongside surface disinfection, the basics matter just as much: frequent handwashing with soap, masks for anyone with symptoms, opening doors and windows when the rain stops, spacing people out as far as the room allows, and coordinating with the district public health centre or medical team for regular symptom checks.

10 reasons shelters and evacuation points should keep Chemgene HLD4H on hand

1. It is listed against RSV and influenza H1N1, the main risks in crowded rainy-season shelters. See the Chemgene HLD4H product page.
2. It covers diarrhoeal germs from shared toilets, with listed activity against norovirus, Salmonella and bacteria.
3. It works fast. The product page states a 1-minute kill time, ideal for frequent wipe-downs in toilets with a queue.
4. It keeps protecting. The page states residual surface protection for up to 14 days, a useful extra layer between cleaning rounds.
5. It suits spaces with children and older adults. The page states it is safe for people when used as directed and lists elderly-care and childcare among its users.
6. It does not damage temple or school property, being non-corrosive to stainless rails, aluminium doors, plastic chairs and rubber flooring.
7. It is economical over many days, diluting up to 1:200 for shelters that must clean several times a day on a tight budget.
8. Volunteers can learn it in minutes. Dilute, spray or wipe, wait the contact time, done. No complex equipment needed.
9. Documentation donors and authorities can check, including Mahidol University, NHS England and EN 14476. See the certificates page.
10. It works from day one to handover, for daily rounds while the shelter is open and the final deep disinfection before the building is returned. Order at Chemgene HLD4H.

Before and after: a shelter with a clear hygiene plan

Example case: a school gym near Bueng Kum that became an evacuation point for a week

Example case (an illustrative scenario explaining the process, not a review from a specific customer)

Khru Wit is a PE teacher asked to look after his school's gymnasium near Bueng Kum, which opened as an evacuation point for about seventy residents. The first two days were chaotic. Everyone helped where they could, but nobody was directly responsible for hygiene.

Day three. After two children started coughing and running a fever, Khru Wit called a short volunteer meeting and organised three shifts, each with people responsible for the toilets, the food point and common areas. The team diluted Chemgene HLD4H according to the label into clearly labelled spray bottles: a stronger mix for the toilets and a separate bottle for tables and rails. A cleaning schedule went up on the toilet door, and whoever finished a round signed their name and the time.

Day four. Khru Wit turned a corner of the gym near a breezy doorway into a symptom area. The two children and their parents moved there with masks, and the district health team came to check on them. Babies and older adults were placed on the opposite side. The food point switched from self-service to volunteers serving, and every family received its own cutlery labelled with their name.

Day eight. As the water receded and residents went home, the team deep-cleaned the whole gym: washing the floor, drying it, then disinfecting the floor, bleacher rails, toilets and sports-equipment store before handing the space back so the school could prepare to reopen.

In this example, nobody could promise that no one else would fall ill. What changed was that the shelter had a system. Volunteers knew what to do, when, and with which product, and people with symptoms were separated before infection could reach the most vulnerable.

Hygiene checklist for temporary shelters

The day the shelter opens

• Appoint someone responsible for hygiene and set up volunteer shifts.
• Set up handwashing or gel points at the entrance, outside the toilets and at the food point.
• Dilute disinfectant per label into bottles labelled with the product name and mixing date; store them out of children's reach.
• Plan the sleeping layout with walkways and designate a symptom area.

Every day

• Disinfect toilets and high-touch points several times; log the time and who did it.
• Wipe meal tables before and after every meal.
• Check on residents' health at least once a day, especially babies, young children and older adults.
• Ventilate whenever the rain stops.
• Bag and tie rubbish daily, particularly used nappies and tissues.

When someone falls ill

• Move them to the symptom area and ask them to wear a mask.
• Inform the health team or the district public health centre.
• If you see danger signs such as laboured breathing, blue lips or drowsiness, get them to a doctor at once.
• Increase wipe-downs of surfaces the sick person uses.

Before closing the shelter

• Sort mats, blankets and cushions; wash or discard according to condition.
• Remove dirt throughout the building, dry it, then disinfect with Chemgene HLD4H.
• Record the cleaning and formally hand the space back to the building's owner.

Frequently asked questions about hygiene in flood shelters

Can we mist disinfectant through the whole hall to kill viruses?

No. Do not spray people or mist disinfectant into a space where people are present. Use Chemgene HLD4H to wipe or spray surfaces that have been cleaned, especially high-touch points, alongside ventilation, masks and handwashing.

How often should toilets be wiped?

In a shelter with dozens to hundreds of people, wipe toilet touch points every two to three hours at busy times and give the toilets a thorough clean at least once a day.

Can Chemgene HLD4H be used near babies and older adults?

The product page states it is safe for people when used as directed and lists childcare and elderly-care settings among its users. Even so, wipe surfaces when nobody is lying right there, do not spray near faces, and keep the area ventilated.

A child in the shelter has a cough and runny nose. How do we know if it is RSV?

RSV and ordinary colds look very similar, and only a doctor can diagnose it. What carers can do is separate children with symptoms, watch for danger signs such as fast breathing, ribs pulling in, wheezing or poor feeding, and seek medical help immediately if they appear.

What dilution should we use?

Chemgene HLD4H can be diluted from 1:30 to 1:200. Follow the label and the supplier's advice. Generally, toilets and surfaces soiled with bodily waste need a stronger dilution than tables and rails.

Besides disinfectant, what should agencies and donors send to shelters?

Hand soap, alcohol gel, masks, rubber gloves, rubbish bags, empty spray bottles, cleaning cloths, individually wrapped cutlery and washable plastic mats all help a hygiene plan work in practice.

What needs to happen before a school or temple is handed back?

Remove belongings and sort bedding, clean off dirt, dry, then disinfect all surfaces, especially toilets, the food point and the symptom area. Record the work and hand the space back to the building's owner.

Protect people in your shelter from a second round of illness

The World Health Disinfection team can advise on dilution, quantities for shelters of different sizes, and a cleaning routine volunteers can realistically keep up.

Order Chemgene HLD4H for Shelters

Call 065-556-6294  |  LINE @whd268  |  worldhealthdisinfection@gmail.com

Related pages

• Chemgene HLD4H medical-grade disinfectant
• Ozone disinfection for buildings (for restoring a building after the shelter closes)
• Test certificates
• Contact us

References

• 2026 Bangkok floods (Wikipedia)
• Al Jazeera: Disaster zone declared across Bangkok
• WHO fact sheets
• CDC: Floods