Not sure if I'm being incredibly dense here, but is it possible to use items on other people?

When my party is out levelling and we run low on HP or MP, whenever I try to use an item on them I end up using it on myself. I've tried every combination of targeting/using items I can think of, so I'm really just wondering if it's even possible.

If it is possible, does it only work with certain items? Does it work with temporary items? Most importantly, how do I do it?

Thanks.