Cold and respiratory disease

Cold and respiratory disease

The links between cold and ill health are complex. They involve not only direct impacts like hypothermia but also the aggravation of several types of chronic diseases, along with an increase in the transmission rates of various bacterial and viral infections. Colder temperatures have been linked with increased exposure to viral infection (Alahmari et al., 2015; Blondeel et al., 2023) and increased crowding indoors promotes the transmission of disease (Mäkinen et al., 2009; Huang et al., 2023). Inhaling cold air, cooling the body’s surface and experiencing cold stress from lowering the core body temperature trigger physiological reactions, such as vasoconstriction in the respiratory tract mucosa and suppression of immune responses (Schaefer et al., 1980; Koskela, 2007; D’Amato et al., 2018). Increased exposure to viral infection is one possible explanation for COPD exacerbation by cold weather (Love and Proud, 2022; Donaldson et al., 2012). In addition, cold weather can cause bronchoconstriction, which can exacerbate COPD (Koskela et al., 1996).

Cold is one of the largest environmental risks in terms of burden of disease in Europe, following only ambient air pollution and noise, and lying far above heat. The health effects of cold are also aggravated by energy poverty. Exposure to cold (including cold waves and generally cold temperatures) has a strong effect on the burden of chronic respiratory illness, causing over 11% of chronic respiratory deaths in Europe. In addition to its effect on chronic respiratory diseases, cold is responsible for almost one in five lower respiratory infection deaths in  EEA member and collaborating countries. Most cold-related preventable mortality is due to respiratory causes (Diaz et al., 2005; Linares et al., 2015; Carmona et al., 2016).

Trends in exposure to cold in Europe and its impacts on health

In Europe, temperature rise due to climate change has been particularly fast in the cold season (Rantanen et al., 2023). Though there is no current evidence that cold-related mortality has consistently decreased in Europe, studies generally predict that as the climate warms, the effects of cold on health will diminish. Assuming a 2.0°C average warming, the population annually exposed in Europe to extreme cold is projected to decrease by two thirds from around 10 million currently by 2100, with strongest absolute reductions projected for southern and northern European countries. Similarly, the number of deaths related to extreme cold events in Europe is projected to significantly decrease (Naumann et al., 2020). But climate change does not mean cold waves will no longer happen; moreover, the decrease in cold-related mortality is not projected to compensate for the expected increase in heat-related mortality (Martinez et al., 2018; Martínez-Solanas et al., 2021; Staddon et al., 2014).

Preventable mortality from cold exposure warrants urgent action, from policies against energy poverty to cold-health action plans. Energy poverty, defined as a household reducing its energy consumption to a degree that negatively impacts the inhabitants' health and wellbeing, is worsening in Europe. With the effect of the COVID-19 crisis and the surge in energy prices compounded by the Russian invasion of Ukraine in February 2022, the proportion of EU-27 residents unable to keep their homes adequately warm has increased from under 6.9% in 2020 to 9.3% in 2022 and 10.6% in 2023. The situation varied across the EU, with the latest data showing the largest share of energy poverty occurring in Spain and Portugal (20.8%) and the smallest share in Switzerland (0.4%) (see Figure 4). It is important to note that several countries have experienced significant declines in this indicator of energy poverty in the last 10 years, notably Bulgaria (-19,8%), Malta (-15,5%), Greece (-13,7%), Cyprus (-10,6%) and Latvia (-10,2%).

Energy poverty tends to disproportionately affect lower income households and those dwelling in low-quality housing (López-Bueno et al., 2020; EC, 2023). Moreover, indoor and outdoor air quality are severely worsened when solid fuel is used to warm homes, a far more common practice in situations of energy poverty.

What the EU is doing about cold exposure

The EU has made energy poverty a policy priority. The concept of energy poverty was first introduced into EU law by the Directive on Common Rules for the Internal Electricity Market (2009/72/EC) and has since mainstreamed into policies for just and fair energy transition over the past decade. In 2019, the EU approved the ‘Clean energy for all Europeans’ package. This energy rulebook includes national energy and climate plans (NECPs), whereby all EU countries outline 10-year national plans to address energy and climate targets. This includes requirements to measure energy poverty and to tackle it wherever it is identified. In October 2021, the Commission published a toolbox of measures proposing actions that EU countries can take to tackle rising energy prices, and protect consumers and businesses. In 2023, the EU established the EU social climate fund, revised the Energy Efficiency Directive (2012/27/EU) and published guidance on energy poverty. In 2024, the Energy Performance of Buildings Directive (EU/2024/1275) entered into force. The renovation wave initiative builds on the aforementioned initiatives and directives, which has tackling energy poverty and worst performing buildings as a main focal point.