Cold Homes and Health

Cold is not simply uncomfortable. It is a physiological stressor, and the evidence linking cold housing to illness and death is consistent across official and independent sources. National Energy Action states that around 10,000 people die each year as a result of living in a cold home¹, and its Warm Homes Healthy Futures programme repeats the figure, putting the average at 10,000 deaths a year from living in a cold home². The same body of work links cold and damp housing to a 30 to 50 per cent increase in respiratory problems².

The temperature at which this begins is lower than many households assume. Official guidance is to heat the home to at least 18°C, and for people aged 65 and over or those with pre-existing health conditions, bedroom temperatures of at least 18°C overnight³. Below that, the risks concentrate in the cardiovascular and respiratory systems, and in the groups least able to respond: older people, those with long-term conditions, and households already in fuel poverty.

The cost falls partly on the NHS. Energy Systems Catapult estimates that the NHS spends up to £856m every year treating illnesses made worse by cold homes⁴. That figure sits alongside a wider problem of scale: estimates of households in fuel poverty run at over six million⁵, and the long-standing definition used across much of the UK turns on spending more than 10 per cent of income on fuel⁷.

Why cold homes damage health: the conditions and the scale

The mechanism is not mysterious. Cold air narrows blood vessels, raises blood pressure and puts additional strain on the heart, while cold and damp air irritates airways already compromised by asthma or chronic obstructive pulmonary disease. National Energy Action lists the conditions cold homes can cause or worsen as heart attacks, strokes, bronchitis and asthma¹. Damp homes, which frequently accompany cold ones, are linked to a 30 to 50 per cent increase in respiratory problems².

The mental health dimension is less often discussed but is measured. A quarter of young people living in cold homes have multiple mental health risks, compared with 1 in 20 in warm homes². That is a fivefold difference in the same age group, and it points to cold housing as a household stressor rather than a purely physical one.

Public Health England has warned of a damaging overlap between the health impacts of living in a cold home and Covid-19¹, a reminder that cold housing compounds whatever else is circulating. The scale is not marginal: with over six million households estimated to be in fuel poverty⁶, the population exposed to these risks is large enough to register in national health statistics.

For a household's energy independence, the health evidence cuts in a particular direction. A cold home is not a neutral choice about comfort; it is a measurable health exposure. The dependence that remains is on the grid and on a supplier for the energy needed to keep rooms at 18°C, and for households that cannot afford that energy, the health cost is borne partly by the NHS rather than by the household alone.

The temperatures that matter: 18°C, and when warmth becomes overheating

The published threshold is straightforward. The Met Office advises heating the home to a temperature of at least 18°C³. For people who are 65 and over or who have pre-existing health conditions, it adds that bedroom temperatures of at least 18°C overnight may be needed³. That overnight figure matters because much of the excess risk in cold weather occurs during sleep, when occupants are least likely to notice a falling temperature.

The 18°C figure is a floor, not a target for every room at every hour. It applies to occupied rooms, and the practical implication is that heating a single room to 18°C is materially different from heating a whole house to that level. Households managing cost often concentrate warmth in one room, which reduces bills but leaves bedrooms and bathrooms below the threshold overnight.

At the other end of the scale, warmth becomes a health issue in its own right. Overheating in UK homes is a recognised problem, and the same households that underheat in winter may overheat in summer, particularly in flats with limited ventilation. The relevant point for this page is that the healthy band is a band: too cold carries cardiovascular and respiratory risk, and too hot carries its own.

Where a household cannot reach 18°C, the evidence points to the underlying cause rather than to behaviour. Fuel poverty, poor insulation and inefficient heating systems are the drivers, and they are addressed through the schemes set out below rather than through advice to sit in a colder room.

Which health conditions are worsened by living cold

The conditions most consistently associated with cold housing fall into four groups, and the same groups appear in both health guidance and scheme eligibility rules.

• Cardiovascular conditions. Heart attacks and strokes are listed by National Energy Action among the conditions cold homes can cause or worsen¹. Cold raises blood pressure and cardiac workload.
• Respiratory disease. Bronchitis and asthma appear in the same list¹, and damp homes are linked to a 30 to 50 per cent increase in respiratory problems². Chronic obstructive pulmonary disease and childhood asthma are specifically named in Warm Home Prescription material⁴.
• Immunosuppression and illnesses affecting the immune system. These appear both in health guidance⁴ and in the eligibility rules for ECO4 Flex and the Great British Insulation Scheme Flex⁸.
• Limited mobility and physical disability. Reduced mobility makes it harder to keep warm and to respond to cold, and it appears as a qualifying condition in the same scheme rules⁹.

Mental health is affected too. The finding that a quarter of young people in cold homes have multiple mental health risks, against 1 in 20 in warm homes², places cold housing among the social determinants of adolescent mental health rather than a separate issue.

The practical consequence is that cold housing does not produce one illness. It aggravates several long-term conditions at once, which is why the health service cost is spread across primary care, hospital admissions and emergency care rather than concentrated in a single budget line.

The scale of the problem: over six million households and around 10,000 deaths a year

Estimates of the number of UK households in fuel poverty vary by source and by definition, and the variation is worth stating plainly rather than smoothing over.

The 2.3 million figure¹⁰ and the six million figure⁶ measure different things: the first counts households that cannot afford adequate heating, the second counts households in or approaching fuel poverty on a broader definition. The 1.8 million figure¹¹ is the number of fuel-poor households the Warm Home Discount is expected to reach in winter 2025/26, which is a scheme coverage number rather than a prevalence estimate.

The death figure is the one that carries the most weight in policy discussion. National Energy Action states that around 10,000 people die each year as a result of living in a cold home¹, and repeats the average of 10,000 deaths a year in its Warm Homes Healthy Futures material². These are estimates of deaths associated with cold housing, not a single official count, and they should be read as such.

For a household, the relevance is that cold housing is a population-level problem with individual consequences. The same conditions that produce the national figures, cardiovascular and respiratory illness in older and vulnerable people, are the ones a household can act on by keeping occupied rooms at 18°C where it can afford to.

Fuel poverty: the 10 per cent definition and who it catches

The long-standing definition of fuel poverty, used in Scotland, Wales and Northern Ireland, is that a household would have to spend more than 10 per cent of its income to keep the home at a reasonable temperature⁷. Ofgem states the same threshold in terms of households needing to spend more than 10 per cent of annual income on fuel to maintain an adequately heated home¹², and the Northern Ireland definition is that a household needs to spend more than 10 per cent of its income on energy costs¹³.

The definition has been refined over time, and the refinements matter for who is caught.

• Including housing benefit. One version counts more than 10 per cent of income including Housing Benefit or Income Support for Mortgage Interest on all household fuel use¹⁰.
• Excluding housing benefit. An alternative version excludes those payments from the income calculation¹⁰. The two produce different household counts.
• Scotland's statutory definition. Under the Fuel Poverty (Targets, Definition and Strategy) (Scotland) Act 2019, a household is in fuel poverty if more than 10 per cent of net income is required to pay for reasonable fuel needs after housing costs, and the remaining income is not enough to maintain an acceptable standard of living. Extreme fuel poverty is set at 20 per cent¹⁴.
• Wales. The Welsh definition is households needing to pay more than 10 per cent of full household income to maintain a satisfactory heating regime¹⁵.
• Scotland's earlier framing. The 2019 Act is also described as applying where a household has to spend more than 10 per cent of income on fuel costs to maintain a satisfactory heating regime¹⁶.

The definition catches households whose income is low relative to their heating need, which in practice means older people on fixed incomes, families with young children, and occupants of poorly insulated homes. The Scottish House Condition Survey 2024 found that 10 per cent of non-fuel-poor households cited affordability as a reason their home was difficult to keep warm, compared with a higher share among fuel-poor households¹⁷. That comparison shows the definition is not capturing a problem unique to fuel-poor households, but it is concentrated there.

The dependence this creates is direct: a fuel-poor household depends on a supplier and a grid for energy it cannot fully afford, and the health consequences fall on the occupants first and the NHS second.

Older people and cold homes: what the figures show

Older people are the group most consistently identified as at risk. The Met Office singles out people aged 65 and over, alongside those with pre-existing health conditions, as needing bedroom temperatures of at least 18°C overnight³. That is a specific, actionable threshold aimed at the group with the highest cold-related mortality.

The health warning extends beyond temperature. Public Health England has warned of a damaging overlap between the health impacts of living in a cold home and Covid-19¹, which is relevant to older people both because of their higher risk from respiratory infection and because cold housing reduces the body's ability to resist it.

Age UK's services reflect the same targeting. Cornwall and Isles of Scilly Winter Wellbeing guidance lists eligibility as living with a long-term health condition, being at risk of poor health, caring for a vulnerable person, having a child aged 19 or under, or worrying about the home being cold or damp¹⁸. Older people appear in that list through the long-term health condition and vulnerability routes rather than through age alone.

For older households, the practical picture is that cold housing risk is compounded by fixed incomes, lower mobility and, in some cases, a reluctance to heat rooms adequately for cost reasons. The health evidence supports keeping occupied rooms at 18°C, and the support routes below exist precisely because many older households cannot reach that level without help.

Warm Home Prescription: heating support prescribed through the NHS

The Warm Home Prescription is a service run by Energy Systems Catapult that adds credit directly to patients' energy accounts and installs energy efficiency measures in their homes for longer-term impact⁴. It has been trialled and refined since 2021, and the Catapult has delivered it in several UK NHS regions while supporting others to design their own versions⁴.

The service is aimed at people whose health is adversely affected by living in a cold home. The conditions it addresses include cardiovascular conditions, respiratory conditions such as chronic obstructive pulmonary disease and childhood asthma, illnesses affecting the immune system, and physical disabilities that limit mobility⁴. It also makes a significant difference to people undergoing treatments such as cancer chemotherapy and renal dialysis, and to people who have just been discharged from hospital⁴.

The trial results, drawn from an independent third-party evaluation of trials between 2021 and 2023, are notable:

• Most households taking part put their heating up by 2 degrees or more⁴.
• Most people said they felt warmer, and as a result, better⁴.
• People receiving a Warm Home Prescription used NHS primary care services less than before⁴.
• Most clinicians said they could see benefits for their patients⁴.
• For every £1 spent, there is a £5 return to society⁴.

The £5 return per £1 spent is a modelled social return rather than a cash saving to the NHS, and it should be read as such. The reduction in primary care use is a more direct measure, though it is reported rather than quantified in the material.

The Warm Home Prescription is not applied for directly by households. It is delivered through NHS regions and referrals come through clinicians, which means the route in is a health professional rather than a form. Households in areas where it operates can ask their clinician whether it is available locally.

Where to get free help: National Energy Action and Age UK advice services

Free advice is available across the UK, though the organisations and phone numbers differ by nation.

National Energy Action provides free advice about energy bills and keeping warm and safe at home, and can also help with benefits advice and income maximisation²³. It offers advice and support to help people across England, Wales and Northern Ireland stay warm and manage energy costs¹⁹, and a British Sign Language interpreter can be requested²³.

In Northern Ireland, NI Energy Advice offers free comprehensive advice on saving energy in the home, energy efficiency grants and other help that may be available²⁴. It is independent and impartial, aimed at domestic householders, and includes referrals to energy grants and other sources of help²⁵. Belfast City Council also lists free advice on saving energy, energy efficiency grants and oil buying clubs²⁶.

In Scotland, Home Energy Scotland offers free advice on improving the energy efficiency of your home²¹. In England, local authority services vary: Birmingham City Council directs households to energy bill help²³, and Bristol's Home Energy Team provides impartial advice to residents and will check ECO Flex eligibility²².

The Energy Ombudsman advises consumers worried about energy bills¹⁹, and Edinburgh City Council offers financial help and energy efficiency support²¹. The practical starting point is the national service for the relevant nation, with local authority teams handling scheme eligibility checks.

Insulation as the lasting fix: the preferred solution

Advice and crisis payments address the symptom. Insulation addresses the cause, and it is the intervention the sector consistently favours. The Department for Communities in Northern Ireland states its long-term ambition as improving the energy efficiency of Northern Ireland's housing stock, thereby reducing carbon emissions and helping to keep homes comfortably warm at an affordable cost²⁷.

The scheme landscape reflects that priority. The Great British Insulation Scheme and ECO4 both include local authority and supplier flex routes for households living in fuel poverty, or those on a low income and vulnerable to the effects of living in a cold home⁸. The Great British Insulation Scheme Flex allows participating local authorities or devolved administrations to refer households they consider to be in fuel poverty or on a low income and vulnerable to cold, who may not qualify through standard criteria²⁸.

Health is written into the eligibility rules. A household can qualify where a person has a severe or long-term health condition that is adversely affected by living in a cold home²⁹, and the qualifying conditions include cardiovascular conditions, respiratory disease, immunosuppression and limited mobility⁹. ECO Flex Route 3 allows a medical professional to identify an occupant whose health conditions may be adversely affected by living in a cold home³⁰, and the same route is described in Ceredigion's ECO4 Flexible Eligibility guidance⁹.

For households, the significance is that insulation is the one intervention that reduces both the health exposure and the ongoing cost. It also reduces dependence: a well-insulated home needs less energy from the grid to reach 18°C, which lowers the household's exposure to price movements and to the supplier relationship. The remaining dependence is on the installer and on the scheme rules, which is why the eligibility routes above matter as much as the measures themselves.