Why Handwashing Matters More During Summer

Summer brings opportunities for sun-soaked enjoyment, from easy-going days outside to crowded festival sites and dining in the open air.

Yet the pleasures of the season also bring a less obvious drawback: a greater risk of infection.

Higher temperatures, more socialising and increased exposure to unfamiliar settings can all make it easier for germs to circulate.

For that reason, handwashing matters particularly during summer. It may not be exciting, but clean hands are a key defence against microbes that can ruin summer plans.

Microbes flourish in warm, damp conditions, while many popular summer activities increase our contact with surfaces, food and water sources through which they can spread.

1. Public lavatories and shared toilets

Festivals, motorway service areas, beaches and campsites commonly depend on public toilet facilities. Because so many people use them, these spaces can provide ideal conditions for bacteria including E coli, salmonella and Staphylococcus aureus.

Viruses, including norovirus and flu, can also be readily passed on through contaminated surfaces. Coronavirus may persist too in environments that are poorly ventilated or not cleaned adequately.

Thoroughly washing your hands after using a public toilet is vital. Hand sanitiser may not be sufficient when hands are visibly soiled.

Even in settings where cleanliness is especially important, such as hospitals, this fundamental precaution is often missed.

Research published in 2025 found that almost half of hospital visitors did not wash their hands after going to the toilet, despite prominent reminders. If handwashing is skipped so often in hospitals, where the danger is clear and facilities are readily accessible, how many more people fail to do it at summer events, where soap and water may be limited?

2. Outdoor eating and food preparation

Barbecues and picnics are central to summer, but they also carry risks. Foodborne pathogens such as salmonella, E coli, Bacillus cereus and Staphylococcus aureus prosper in warmer conditions. Meat that has not been cooked properly, inadequate hand hygiene and food left in direct sunshine can quickly turn a celebration into food poisoning.

Fungi including Aspergillus may also grow on food and create mycotoxins. These toxic substances can cause nausea, organ damage and even longer-term harm if consumed.

Wash your hands both before and after preparing food, particularly after touching raw meat or shared items such as picnic tables, barbecue utensils and cool boxes.

3. Swimming and water play

Potentially harmful germs can be found in lakes, rivers, pools and the sea. Parasites such as cryptosporidium and giardia may lead to gastrointestinal illness, and they are frequently resistant to chlorine. Faecal bacteria may be present in beach sand and seawater as well.

Whether you are swimming, paddling or simply making sandcastles, wash or sanitise your hands before eating or touching your face.

4. Camps, playgrounds and festivals

During summer, children can be especially susceptible to infection in group environments, including holiday camps, soft play centres and playgrounds.

One US study identified 229 youth camp-associated gastroenteritis outbreaks over seven years. Norovirus, salmonella and Shiga toxin-producing E coli were among the common causes. The latter is a particularly dangerous type of E coli that can result in serious illness and even kidney failure.

In a single incident, 20 campers fell ill and three were hospitalised after consuming undercooked beef prepared over a campfire. Shared toilets, communal food preparation and closely packed sleeping arrangements all make hand hygiene more important.

But isn't it good to 'get a bit dirty'?

Some people think allowing children to get dirty strengthens their immune system. Exposure early in life to natural microbes in soil, animals or the wider environment can indeed aid immune development, but that is very different from not washing hands after using the toilet or before eating.

Not washing hands does not build immunity; it raises the likelihood of becoming ill. There are no credible studies showing that poor hygiene benefits health.

Instead, unwashed hands are among the main causes of preventable infections around the world. The consequences can be particularly severe for young children, older people and those with compromised immune systems.

Hand hygiene is straightforward, inexpensive and effective, and its importance is never greater than in summer. The hospital toilet study demonstrates that we cannot simply presume people wash their hands correctly, even in places intended to safeguard health.

Add the disorder of a campsite or the diversions of a music festival, and remembering becomes easier to overlook.

So, whether you are walking, camping or dancing in a field, wash your hands with soap and clean running water for at least 20 seconds, then dry them thoroughly, as damp hands transmit germs more easily. If soap and water are unavailable, use hand sanitiser containing at least 60 percent alcohol. Ideally, carry some in your bag rather than depending on public facilities.

Manal Mohammed, Senior Lecturer, Medical Microbiology, University of Westminster

This article is republished from The Conversation under a Creative Commons licence. Read the original article.