A platoon of infantry in the field is 20-30 guys with rifles and machine-guns. Most of the time, but not always. In reality, the total number of people could approach a hundred because of all the special units that often get attached to infantry platoons. It's frequently forgotten that when you "reinforce" the infantry, the reinforcing units generally end up attached to an infantry platoon. It adds up. In addition to a medic or two, you might have some additional radio operators with special equipment, one or two chemical warfare people, some heavy weapons people (more machine-guns and rocket launchers), anti-tank troops (lugging a Javelin missile or two), a anti-aircraft missile team (with Stingers) and maybe a mortar team (81mm mortars). Then there's an artillery forward observer team, an air force forward observer team and, if you are a marine platoon, a naval gunfire forward observer team. Add some combat engineers, maybe a tank or two, a translator and perhaps an intel weenie, and you have yourself quite a little army there. Pretty heady stuff for a lieutenant. It gets worse, of course, for if the shooting starts you have to worry about where all these other contingents are and what they are doing. But that's another story.