How do i make it so if you look at something youll die?

deathPart = part  -- Pass there your part, that part if you place cursor on it you will die.

local plr = game.Players.LocalPlayer -- define localplayer

local mouse = plr:GetMouse() -- get player's mouse

while wait() do -- make infinite checking loop
    if mouse.Target == deathPart then  -- if player cursor is placed on deathPart. Make them watch from first person or make invisible or barely visible part across whole area you want them to die when they look there.
        plr.Character.Humanoid.Health = 0 -- kill player
    end
end