If you store your lenses better to keep them away from the moisture and humid conditions. If you use a lens taken out a cold condition straight away to the hot humid conditions it forms condensations between lens elements and that's where the fungus in the air starts to grow. So the idea is to eliminate moisture and this can be done keeping all the lenses well-sealed containers ( Plastic bags and airtight containers ) with de-humidifiers like Silica gels. So this is an especial situation while using the photo tools during a visit in a tropical country, in the places like Sahara or in Iceland or alps mountains. Cold or hot weather can cause lot of condensations in cameras.