Does heating really make eczema worse, or is it just the cold outside?

Heating is often the larger contributor of the two. Heating systems lower relative humidity as a direct consequence of raising temperature without adding moisture. A heated home can have lower humidity than the cold outdoor air, meaning the indoor environment intended as a refuge from winter weather can present an equal or greater challenge to the skin barrier.

What indoor humidity level is best for eczema?

40 to 50 percent relative humidity is the generally recommended target. Below 30 percent, the drying effect on skin becomes significant. Above 60 percent, dust mite proliferation and mould growth become more likely, both of which are separate eczema triggers. A hygrometer allows you to monitor this accurately rather than guessing.

Do I need a humidifier in every room, or just the bedroom?

The bedroom is the priority, since this is where your child spends the most consecutive hours in a heated, enclosed space, typically overnight. If your child spends significant daytime hours in another heated room (a living area, for instance), humidity support there is also worthwhile, but the bedroom overnight period generally has the largest cumulative impact.

Can I just turn the heating off to avoid the humidity problem?

Not recommended. A cold home carries its own risks and discomforts, and cold air itself (independent of heating) also has lower humidity than warm air, so simply avoiding heating does not solve the underlying seasonal humidity challenge. The better approach is to heat to a comfortable, moderate temperature (18 to 20 degrees Celsius) and actively manage humidity alongside it, rather than avoiding heating altogether.

Indoor Heating and Eczema: Managing Dry Air This Winter

By Kelly Northey, Certified Postpartum Nutrition Professional

Founder of Nella Vosk • 14+ years supporting families across motherhood, feeding, and early childhood wellbeing

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Indoor Heating and Eczema: Managing Dry Air This Winter

This article is part of the Nella Vosk Complete Guide to Eczema-Friendly Clothing: Fabrics, Fit & Science for Australian Families, and completes the Winter Eczema Prep series alongside preparing your eczema child for winter, why eczema gets worse in winter, and the best winter skincare routine for babies with eczema. This article addresses the environmental piece of the winter puzzle: what heating actually does to indoor humidity, and how to manage it so your home supports your child’s skin rather than working against it.

Most parents assume that once they escape the cold outdoors and get their child into a warm, heated home, the eczema challenge of winter is largely solved. In reality, indoor heating frequently makes the humidity problem worse, not better. Heating systems raise temperature without adding moisture, which lowers relative humidity, sometimes leaving a heated home with drier air than the cold outdoors it was meant to provide relief from.

Why Heating Lowers Humidity (Even Though It Feels More Comfortable)

Relative humidity is a measure of how much water vapour is in the air relative to the maximum the air could hold at that temperature. Warm air can hold significantly more water vapour than cold air. When a heating system raises the temperature of a room without adding any moisture, the absolute amount of water in the air stays the same, but the air’s capacity to hold water increases. The result is a drop in relative humidity, even though the room feels warmer and more comfortable.

This is why a heated home in winter can have indoor humidity levels of 20 to 30 percent or lower, well below the 40 to 60 percent range generally considered comfortable for skin, while the same home might sit at 40 to 50 percent humidity on a mild, unheated day. The warmth is genuinely more comfortable in the moment, which is exactly why parents do not intuitively connect a heated room to a drying effect on their child’s skin.

For the full physiological explanation of why this drop in humidity accelerates water loss from eczema-prone skin specifically, see why eczema gets worse in winter (and what to do about it).

How Different Heating Systems Compare

Reverse-cycle air conditioning (heat pump heating)

One of the most common heating systems in Australian homes. Reverse-cycle systems are efficient at raising temperature but are among the more drying heating types, because the heating process circulates and reheats the same indoor air repeatedly without adding moisture, and the system’s dehumidifying function (built in for cooling mode) can further reduce humidity even in heating mode on some models.

Ducted gas heating

Ducted heating raises temperature efficiently across a whole home but shares the same fundamental limitation: it heats air without adding moisture, producing the same relative humidity drop as reverse-cycle systems.

Wood fires and gas log fires

Open combustion heating (wood fires, unflued gas heaters) can be particularly drying, both because of the direct heating effect and because combustion consumes oxygen and can draw in additional dry outdoor air to replace it, further reducing indoor humidity. Unflued gas heaters also carry separate air quality and ventilation considerations that are worth discussing with your GP if your child has any respiratory sensitivity alongside their eczema.

Electric panel heaters and column heaters

Generally similar in drying effect to reverse-cycle systems: they raise temperature without adding moisture. Panel heaters used in a smaller, more enclosed room (such as a nursery) can produce a more concentrated drying effect than a larger ducted system heating a whole home, simply because the same heat output is concentrated in less air volume.

No common heating system available in Australian homes adds moisture as a byproduct of heating. All of them will lower relative humidity to some degree. The practical implication is not to avoid heating (a cold home carries its own health and comfort problems) but to actively counter the humidity drop that heating causes.

Managing Indoor Humidity: The Practical Approach

Target humidity range

Aim for indoor humidity of 40 to 50 percent in your child’s bedroom and main living areas. Below 30 percent, the drying effect on skin becomes significant. Above 60 percent, indoor humidity starts to support dust mite proliferation and mould growth, both of which are separate eczema triggers. The 40 to 50 percent range balances skin barrier support against these other risks.

Using a humidifier effectively

A humidifier is the most direct way to counter the humidity drop caused by heating. For a full breakdown of humidifier types (ultrasonic, cool mist, evaporative, warm mist) and how to choose and maintain one safely for a child’s bedroom, see the dedicated guide: humidifiers and eczema: a soothing solution. The key points to combine with that guide: place the humidifier away from the child’s direct sleeping position (close enough to affect the room, not so close that condensation forms on nearby surfaces), monitor humidity with a simple hygrometer rather than guessing, and clean the humidifier according to the manufacturer’s instructions, since a poorly maintained humidifier can introduce mould or bacteria into the air it is meant to be improving.

Positioning your child’s bed away from direct heat sources

Avoid placing a cot or bed directly in front of a heating vent, radiator, or panel heater, where the localised drying effect is strongest
If ducted heating vents cannot be relocated, a vent deflector can redirect airflow away from the sleeping area without closing off the heating to the room entirely
For wall-mounted reverse-cycle units, position the bed outside the direct airflow path where possible

Setting the right temperature, not just the right heating

Keep the bedroom at 18 to 20 degrees Celsius rather than heating to a warmer temperature ‘to be safe’ in cold weather. A room heated beyond this range does not provide additional comfort or safety benefit and increases both the overheating risk (a separate eczema trigger, especially relevant with sleeping bags and layered clothing) and the humidity-lowering effect of the heating system working harder to reach a higher target.

Ventilating briefly, even in winter

A few minutes of fresh air exchange daily, opening a window briefly during the warmest part of the day, helps offset the stagnant, repeatedly-reheated air that accumulates in a closed-up winter home. This does not need to be long enough to significantly cool the room; brief exchange is sufficient to refresh the air without undoing the heating.

Signs Your Indoor Air Is Too Dry

Static electricity is noticeably more frequent (a simple, non-technical indicator that humidity has dropped significantly)
Your own skin, lips, or sinuses feel drier than usual, even if you do not have eczema
Your child’s eczema is worse specifically in the rooms that are heated most, compared to unheated areas of the home
Wooden furniture or floorboards show small gaps or cracking, an indicator that ambient humidity has dropped enough to affect materials beyond skin
A hygrometer (an inexpensive, widely available humidity monitor) reads below 30 percent

A hygrometer is the most reliable way to know for certain rather than relying on subjective signs. Small digital hygrometers are inexpensive and widely available, and knowing your actual indoor humidity removes the guesswork from deciding whether a humidifier or other intervention is needed.

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Frequently Asked Questions

: Heating is often the larger contributor of the two. Heating systems lower relative humidity as a direct consequence of raising temperature without adding moisture.

A heated home can have lower humidity than the cold outdoor air, meaning the indoor environment intended as a refuge from winter weather can present an equal or greater challenge to the skin barrier.
: 40 to 50 percent relative humidity is the generally recommended target. Below 30 percent, the drying effect on skin becomes significant.

Above 60 percent, dust mite proliferation and mould growth become more likely, both of which are separate eczema triggers. A hygrometer allows you to monitor this accurately rather than guessing.
: All common heating systems (reverse-cycle, ducted gas, panel heaters) lower relative humidity to a similar degree, since none of them add moisture as part of the heating process. Open combustion heating (wood fires, unflued gas heaters) can be particularly drying and carries additional air quality considerations.

The heating type matters less than actively managing humidity alongside whichever system you use.
: The bedroom is the priority, since this is where your child spends the most consecutive hours in a heated, enclosed space, typically overnight.

If your child spends significant daytime hours in another heated room (a living area, for instance), humidity support there is also worthwhile, but the bedroom overnight period generally has the largest cumulative impact.
: Not recommended. A cold home carries its own risks and discomforts, and cold air itself (independent of heating) also has lower humidity than warm air, so simply avoiding heating does not solve the underlying seasonal humidity challenge.

The better approach is to heat to a comfortable, moderate temperature (18 to 20 degrees Celsius) and actively manage humidity alongside it, rather than avoiding heating altogether.

Next Steps

Understanding that indoor heating actively works against skin hydration, rather than being a neutral or automatically helpful winter comfort, changes how you approach the indoor environment. Target 40 to 50 percent humidity, monitor it with a hygrometer rather than guessing, position sleeping areas away from direct heat sources, and combine environmental management with the skincare and clothing adjustments covered elsewhere in this series.

This completes the Winter Eczema Prep series. Return to preparing your eczema child for winter: the complete guide for the full checklist bringing skincare, clothing, and environment together, or to the complete guide to eczema-friendly clothing for the year-round framework.

Also in this cluster:

Preparing your eczema child for winter: the complete guide — the overview and seasonal preparation checklist
Why eczema gets worse in winter (and what to do about it) — the transepidermal water loss mechanism behind the humidity problem
The best winter skincare routine for babies with eczema — the skincare adjustments that work alongside environmental management
Humidifiers and eczema: a soothing solution — the dedicated guide to humidifier types, selection, and safe use
How to create an eczema-friendly bedroom — the year-round bedroom environment framework

Explore the Bamboo Bubby by Nella Vosk eczema pyjamas and sleepwear for kids and adult eczema sleepwear range — breathable, thermoregulating fabric designed to work with a well-managed indoor environment, not against it.

Author Bio

Written by Kelly Northey, Certified Postpartum Nutrition Professional (CPPNP) and founder of Nella Vosk.

As the creator of the Bamboo Bubby eczema clothing range, Kelly has spent over 16 years helping Australian families understand the often-overlooked environmental factors, like indoor heating, that quietly undermine an otherwise well-managed eczema routine.