Published online 2018 May 30 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 … Continue reading The impact of cold on the respiratory tract and its consequences to respiratory health – NCBI (2018)