condensation /black mould in kids bedroom window sill

[squirtycream]

we have condensation on the kids window which has turned into black mould around the sill of the windows. managed to clean most of it off, but should i be concerned?

i had a humidifier on for 3 nights last week, could this have caused it? however this morning the window did have a bit of condensation and i didnt have the humidifier on, the central heating radiator is below the window?

any suggestions what to do?

thanks

Ventilation--open the window a little bit every day, no matter what the temperature is. Wipe the moisture off the windowpanes and woodwork every morning.

thanks abr1de makes sense will give it a try.. although brrrr

I know!