[Melody Pond]

If there are a lot of cuts then a bandage might be best as it will cover them all at once.
If you use plasters you may have to use more than one which will look odd and obvious.
If you just have a bandage covering them all it will not show how many cuts there are and you could say it is just one and you could tell people you fell or something.

Also as for clothes, http://www.newlook.com/shop/womens/s...louses_1260060
There are some cute shirts here, some long sleeve and some 3/4 sleeve which will cover the top of your arms but they are thin and summery.
Or wear cardigans like this http://www.newlook.com/shop/womens/t...igan_222039702
They are really thin and light so they won't make you too warm and you can push the sleeves up.
Just having a little look and there are shirts and blouses that are light but have sleeves. see, http://www.hm.com/gb/subdepartment/L...63716&size=100