PlayerInfo.cs

using UnityEngine;
using System.Collections;
using UnityEngine.Networking;

public class PlayerInfo : NetworkBehaviour
{
    [SyncVar] public int Health = 100;
    public TextMesh tm;

    void Start ()
    {
        transform.name = "Player " + GetComponent<NetworkIdentity> ().netId.ToString ();
    }
    void Update()
    {
        tm.text = transform.name + "/Health "+Health;
    }

    public void GetDamage(int dmg)
    {
        Health -= dmg;
    }

    void OnGUI()
    {
        if (isLocalPlayer)
        {
            GUI.Label(new Rect(Screen.width-100,25,200,50),"Health: "+Health);
        }
    }
}