This will depend on where exactly the first aid kit will be used. Indeed, if the wildlife and climate are drastically different in certain parts of the world, then it stands to reason that a first aid kit should be adapted to these different contexts. There are, however, a few things that no first aid kit should be without, such as bandages, antiseptic wipes, gauze, surgical tape, condoms, pain relief medication, and perhaps something containing an antihistamine. This will, of course, vary wherever you are headed or based, but a first aid kit would feature some gaping holes without the items listed above.