HealthScript.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;

public class HealthScript : MonoBehaviour
{

    public static int healthValue = 100;
    Text health;
    void Start()
    {
        health = GetComponent<Text>();
    }

    // Update is called once per frame
    void Update()
    {
        health.text = "Health:" + healthValue;
        if (healthValue <= 1) 
        {
            Time.timeScale = 0;
            health.text = "Game Over";
        }
    }
}