One of the many problems the cold weather causes is mould, due to condensation that forms on windows. It doesn't just look bad, but it is also potentially harmful to your health.
Mould produces tiny particles called spores, and if inhaled these can cause health problems for those who are allergic or sensitive to them.
However, depending on how old your home is and what the ventilation is like, it's hard to keep it completely at bay.
