The impact of cold on the respiratory tract and its consequences to respiratory health

Abstract

The increasing use, and sometimes the abuse, particularly in industrialized countries of air conditioning at home, in car, hotel and shopping centres has highlighted new emerging public health issues, resulting from exposure of the airways to cool air or, more properly, resulting from sudden temperature changes. This is part of a wider problem, relating to air quality in indoor environment, such as homes or offices, where people spend more than 90% of their time. In particular, if indoor exposure occurs quickly and without any gradual adaptation to a temperature 2°–3° lower than the external temperature and especially with a 5° difference (avoiding indoor temperature below 24°) and an humidity between 40 and 60%, there is a risk of negative consequences on the respiratory tract and the patient risks to be in a clinical condition characterized by an exacerbation of the respiratory symptoms of his chronic respiratory disease (asthma and COPD) within a few hours or days. Surprisingly, these effects of cold climate remain out of the focus of the media unless spells of unusually cold weather sweep through a local area or unstable weather conditions associated with extremely cold periods of increasing frequency and duration. Moreover, the energy consumed by air conditioning induces an increase of CO2 in atmosphere with increase of global warming. There is a need to better define the consequences of repeated exposure to cold air and the mechanisms by which such exposure could modify airway function and affect the outcomes of patients with pre-existing airway disease. This could help to promote adequate policy and public health actions to face the incoming challenges induced by climate change and global warming.

Ciliary beat frequency in children with adenoid hypertrophy

“…We examined patients with AH only in certain months of the year (from June to September before adenoidectomy, respectively from January to April after adenoidectomy), therefore we can not clearly assess potential changes of CBF depending on the season of the year. Seasonal allergy and allergic inflammation, increased incidence of acute viral respiratory infections in certain months as well as other environmental factors (exposure of the airways to cold air, sudden temperature changes, active or passive cigarette smoking or exposure to air pollutants) could also influence the CBF.…”

“…Adenoid hypertrophy (AH) is a common disorder in the pediatric population, especially in preschool-aged children. According to a recent meta-analysis, its prevalence in children and adolescents is 34.46%. 1 Enlarged adenoids cause a posterior nasal obstruction, which leads to typical symptoms, such as mouth breathing, speech anomalies, snoring, and obstructive sleep apnoea syndrome (OSA), as well as recurrent respiratory infections (RRI).…”

Highlights and recent developments in airway diseases in EAACI journals (2018)

“…The sample was collected using commercially available low volume air sampling pumps and DUSTREAT ® dust samplers and quantified at a very low detection limit using a MARIA ® immunoassay . The effect of air conditioning and cold air on asthmatics has been recently reviewed . The sudden change in temperature when entering an air‐conditioned space can exacerbate the respiratory symptoms of patients with asthma and COPD.…”

“…71 The effect of air conditioning and cold air on asthmatics has been recently reviewed. 72 The sudden change in temperature when entering an air-conditioned space can exacerbate the respiratory symptoms of patients with asthma and COPD.…”

Contemporary Enterovirus D68 strains show enhanced replication and translation at 37°C

“…The propensity of a respiratory pathogen to induce severe respiratory distress can be partly linked to its ability to replicate in the lower respiratory tract. The upper respiratory tract is approximately 32°C due to the intake of cool ambient air, while the lower airways are around 37°C, closer to core body temperature [51]. When respiratory viruses replicate poorly at 37°C, their infections are often restricted to the upper airways, limiting the potential for damage to the lower respiratory tract and ultimately mitigating disease severity.…”