Weather is something we can't influence that is why we will try our best to re-book or find the best solution for you.
When you book activity we will let you know everything you need to know about it. But in general, for water activities, you need swimwear and towel, for caving you need warm clothes and for everything else clothes, that you feel comfortable wearing.
Of course, you can! But we are not responsible if something happens to it.