Mouldy

We don't have a bed yet, just mattresses on the floor. I've slept like that for years in the Netherlands and never had a problem. Now within 1 week, the mattress was soaking wet (probably also due to my illness and the profuse sweating caused by it, yuk) and starting to get mouldy! And of course it is raining today, so no chance of putting it in the sun. Been trying to get it dry before the gas heater. Hope it works. No idea if you have to treat it with special anti-mould stuff or anything. Bummer.