Extreme heat is increasingly common in Australia and around the world and besides making us uncomfortable, it can harm our health. For example, exposure to extreme heat can exacerbate existing medical conditions, or cause problems such as heat stroke.

Due to a combination of physiology and behaviour, children are potentially more vulnerable to severe heat-related illness such as heat stroke or heat exhaustion.

But these are not the only heat-related health issues children might experience on a very hot day. In a new study, we looked at emergency department (ED) visits and unplanned hospital admissions among children in New South Wales on heatwave days.

We found a significant increase in children attending hospital compared to milder days – with a range of health issues.

Why are children more vulnerable in the heat?

Sweating is the main way we lose heat from our bodies and cool down.

Children have a greater skin surface area to body mass ratio, which can be an advantage for sweating – they can lose more heat through evaporation for a given body mass. But this also means children can lose fluids and electrolytes faster through sweating, theoretically making them more susceptible to dehydration.

Meanwhile, younger children, particularly babies, can’t sweat as much as older children and adults. This means they can’t cool down as effectively.

Children in general also tend to engage in more outdoor physical activity, which might see them more exposed to very hot temperatures.

Further, children may be less in-tune to the signals their body is giving them that they’re overheating, such as excessive sweating or red skin. So they might not stop and cool down when they need to. Young children especially may not recognise the early signs of heat stress or be able to express discomfort.

Our study

We wanted to examine children’s exposure to extreme heat stress and the associated risks to their health.

We measured extreme heat as “heatwave days”, at least two consecutive days with a daily maximum temperature above the 95th percentile for the relevant area on a universal thermal climate index. This ranged from 27°C to 45°C depending on the area.

We assessed health outcomes by looking at ED visits and unplanned hospital admissions among children aged 0–18 years from NSW between 2000 and 2020. This totalled around 8.2 million ED visits and 1.4 million hospital admissions.

We found hospital admissions for heat-related illness were 104% more likely on heatwave days compared to non-heatwave days, and ED visits were 78% more likely. Heat-related illness includes a spectrum of disorders from minor conditions such as dehydration to life-threatening conditions such as heat stroke.

But heat-related illness wasn’t the only condition that increased on heatwave days. There was also an increase in childhood infections, particularly infectious enteritis possibly related to food poisoning (up 6% for ED visits and 17% for hospital admissions), ear infections (up 30% for ED visits and 3% for hospital admissions), and skin and soft tissue infections (up 6% for ED visits and 4% for hospital admissions).

We know many infectious diseases are highly seasonal. Some, like the flu, peak in winter. But heat and humidity increase the risk of certain infections caused by bacterial, viral and fungal pathogens.

For example, warmer weather and higher humidity can increase the survival of bacteria, such as Salmonella, on foods, which increases the risk of food poisoning.

Hot weather can also increase the risk of ear infections. Children may be at greater risk during hot weather because they often swim or play at the beach or pool. Water can stay in the ear after swimming and a moist environment in the ear canal can cause growth of pathogens leading to ear infections.

Which children are most vulnerable?

During heatwaves, we found infants aged under one were at increased risk of ED visits and hospital admission for any reason compared to older children. This is not surprising, because babies can’t regulate their body temperature effectively and are reliant on their caregivers to keep them cool.

Our study also found children from the most disadvantaged areas were more vulnerable to heat-related illness on heatwave days. Although we don’t know exactly why, we hypothesised families from poorer areas might have limited access to air-conditioning and could be more likely to live in hotter neighbourhoods.

Keeping kids cool: tips for parents

The highest levels of heat exposure on hot days for young children is usually when they’re taken outside in prams and strollers. To protect their children from direct sunlight, parents often instinctively cover their stroller with a cloth such as a muslin.

However, a recent study from our group showed this actually increases temperatures inside a stroller to as much as 3–4˚C higher than outside.

But if the cloth is wet with water, and a small fan is used to circulate the air close to the child, stroller temperatures can be 4–5˚C lower than outside. Wetting the cloth every 15–20 minutes (for example, with a spray bottle) maintains the cooling effect.

When young children are not in a stroller, and for older children, there are a few things to consider to keep them cool and safe.

Remember temperatures reported on weather forecasts are measured in the shade, and temperatures in the sun can be up to 15˚C higher. So sticking to the shade as much as possible is important.

Exercise generates heat inside the body, so activities should be shortened, or rescheduled to cooler times of the day.

Sunscreen and hats are important when outdoors, but neither are especially effective for keeping cool. Spraying water on the child’s skin – not just the face but arms, legs and even the torso if possible – can help. Wetting their hats is another idea.

Proper hydration on hot days is also essential. Regular water breaks, including offering water before, during and after activity, is important. Offering foods with high water content such as watermelon and orange can help with hydration too.

Wen-Qiang He, Research Fellow in Biostatistics and Epidemiology, Faculty of Medicine and Health, University of Sydney; James Smallcombe, Post-doctoral Research Associate, Faculty of Medicine and Health, University of Sydney; Natasha Nassar, Professor of Paediatric and Perinatal Epidemiology and Chair in Translational Childhood Medicine, University of Sydney, and Ollie Jay, Professor of Heat & Health; Director of Heat & Health Research Incubator; Director of Thermal Ergonomics Laboratory, University of Sydney

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

Around one in ten Australians say they follow a gluten-free diet.

This means eliminating common foods – such as bread, pasta and noodles – that contain gluten, a protein found mainly in wheat, barley and rye.

Not everyone who follows a gluten-free diet has an underlying condition. But if you experience nausea, bloating or stomach pain after eating gluten, it could be the sign of a gluten intolerance, or coeliac disease.

While gluten intolerance and coeliac disease share many similar symptoms, one can cause intestinal damage and malnutrition. So, what’s the difference?

What is coeliac disease?

Coeliac disease is an autoimmune disease. This means the body mistakenly starts attacking healthy cells and tissue – in this case, in the small intestine – causing inflammation.

It affects around one in 70 Australians, but only 20% of this group are diagnosed.

If you have coeliac disease, eating foods that contain gluten can damage your villi, structures in the small intestine that help the body absorb nutrients.

Following a meal containing gluten, you may experience digestive problems including diarrhoea, bloating, nausea, gas and abdominal pain.

Gluten can also cause non-digestive symptoms such as brain fog, headaches, dermatitis herpetiformis (an itchy, blistery skin rash), joint pain and fatigue.

In the long term, untreated coeliac disease can lead to malnutrition because the damaged villi can’t absorb nutrients from food. It can also reduce bone mineral density and has been linked to neurological disorders such as epilepsy and dementia.

How is coeliac disease diagnosed?

For an accurate diagnosis, you must not have eliminated gluten from your diet yet. This is so its effect on your digestive system can be measured.

A diagnosis involves blood tests followed by biopsies of the small intestine using an endoscope (an instrument with a light that can look inside the body).

Blood tests look for antigens – markers of a reaction to gluten – while the biopsy inspects any damage to the villi in the intestine.

In some cases, a capsule endoscopy, where a pill-sized camera is swallowed, is used to look at the intestine and observe for damage.

What about gluten intolerance?

People with gluten intolerance experience similar symptoms to coeliac disease. The difference is, after consuming gluten, there is no autoimmune response or intestinal damage.

Gluten intolerance is sometimes known as non-coeliac gluten sensitivity.

An estimated 1% of Australians live with a gluten intolerance, but only 12 in every 100 of this group are diagnosed by a doctor.

Doctors will rule out coeliac disease and wheat allergies as a first step for a person with symptoms related to eating gluten.

Once these have been ruled out, a gluten-free diet trial, supervised by an accredited practising dietitian, might be recommended to see if symptoms improve.

A formal diagnosis of gluten intolerance can only be confirmed using a highly complex dietary trial that compares the effect of gluten and a placebo over at least eight weeks.

This form of scientific study is very labour-intensive and not very common.

So instead many people just choose to eliminate gluten, without a diagnosis.

Extreme sensitivity to gluten

Coeliac disease is more severe than gluten intolerance and sensitivity can vary among those diagnosed.

Even traces of gluten can trigger symptoms. This means a strict, lifelong, gluten-free diet essential.

It also means people with coeliac disease have to be careful about cross-contamination. For example, using the same knife, chopping board or toaster to cut or toast gluten-free bread and regular bread can transfer gluten particles and cause a reaction.

According to the latest studies, consuming just 50mg of gluten per day is enough to cause intestinal damage for people with coeliac disease.

For context, a slice of whole-wheat bread contains about 4,800mg of gluten, meaning 50mg is around 1/100th of a slice of bread.

A small amount of gluten won’t affect someone with gluten intolerance in the same way. They may have temporary symptoms, but won’t experience intestinal damage.

However, the symptoms and their severity can vary from person to person, depending on their individual sensitivity.

Should I cut out gluten, just in case?

You might be wondering if there is a downside to avoiding gluten, if you don’t have coeliac disease or an intolerance.

There can be.

Grain foods that contain gluten are rich in essential nutrients such as fibre, folate, iron and B-group vitamins.

Avoiding gluten when you don’t need to can lead to nutritional deficiencies.

Gluten-free products can also be more expensive and are sometimes higher in sugar, salt and fat to help compensate for texture and taste.

Before making any changes to your diet, it is best to speak with an accredited practising dietitian to make sure you’re not missing out on important nutrients.

So, what if you have symptoms?

Common signs of a gluten intolerance or coeliac disease include bloating, diarrhoea or constipation, and stomach pain. Both conditions can trigger non-gastrointestinal symptoms such as headaches, fatigue and joint pain.

If these symptoms sound familiar, it’s best to speak to a health-care professional who may test you for coeliac disease and/or a wheat allergy before eliminating gluten from your diet.

Remember, self-diagnosing and removing gluten without proper guidance might do you more harm than good.

If your symptoms concern you, speak to your GP, a gastroenterologist or a qualified dietitian. Dietitians Australia has a list of accredited practising dietitians.

Yasmine Probst, Professor, School of Medical, Indigenous and Health Sciences. Advanced Accredited Practising Dietitian, University of Wollongong and Olivia Wills, Associate Lecturer, Nutrition and Dietetics, University of Wollongong

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