I tried to make a god mode when the player equips the tool, it did not work what do I do?

local tool = script.Parent
local HP = 10000

while tool.Equipped == true do
    local hum = tool.Parent:FindFirstChild("Humanoid")
    hum.Health = hum.Health + HP
    wait()
end

I tried to make it so whenever the tool is equipped the player's HP just keep on increasing, I think that "tool.Equipped" part was wrong, can someone help?