Attempt to call global?

currentTemp=game.Workspace:WaitForChild("TemperatureValue")
AlarmMinorS=game.Workspace.AlarmMinor
AlarmMajorS=game.Workspace.AlarmMajor
MainframeStatus=game.Workspace.MainframeStatus.SurfaceGui.TextLabel

function alarmMinor()
	if currentTemp.Value >= 700 then
		AlarmMinorS:Play()
		AlarmMajorS:Stop()
		--
		MainframeStatus.Text = "LavaBlast://Core_Status/Issue"
		MainframeStatus.TextColor3 = Color3.new(255, 85, 0)
		--
		local firethree = workspace.Mainframe_Status_Fire_Parts:GetChildren()
		for i = 1, #firethree do
    	firethree[i].Fire.Enabled = false
		--
		local mainframelights = workspace.MainframeLights:GetChildren()
		for i = 1, #mainframelights do
    	mainframelights[i].Light.PointLight.Color = Color3.new(1, 170/255, 0)
		mainframelights[i].Light.PointLight.Color = Color3.new(255, 170/255, 0)
		mainframelights[i].Light.BrickColor = BrickColor.new("Orange")
		end
	end
end
		
function alarmMajor()
	if currentTemp.Value >= 1000 then
		AlarmMajorS:Play()
		AlarmMinorS:Stop()
		--
		local emergencylightson = workspace.EmergencyLights:GetChildren()
		for i = 1, #emergencylightson do
    	emergencylightson[i].Toggle.Enabled = true
		--
		MainframeStatus.Text = "LavaBlast://Core_Status/Major"
		MainframeStatus.TextColor3 = Color3.new(255, 0, 0)
		--
		local fireone = workspace.Mainframe_Status_Fire_Parts:GetChildren()
		for i = 1, #fireone do
    	fireone[i].Fire.Enabled = true
		--
		local mainframelightstwo = workspace.MainframeLights:GetChildren()
		for i = 1, #mainframelightstwo do
    	mainframelightstwo[i].Light.PointLight.Color = Color3.new(1, 0, 0)
		mainframelightstwo[i].Light.PointLight.Color = Color3.new(1, 0, 0)
		mainframelightstwo[i].Light.BrickColor = BrickColor.new("Red")
		end
	end
end

		
function normalTemperature()
	if currentTemp.Value < 699 then
		AlarmMinorS:Stop()
		AlarmMajorS:Stop()
		MainframeStatus.Text = "LavaBlast://Core_Status/Stable"
		MainframeStatus.TextColor3 = Color3.new(255, 255, 255)
		local fireone = workspace.Mainframe_Status_Fire_Parts:GetChildren()
		for i = 1, #fireone do
    	fireone[i].Fire.Enabled = false
		--
		local mainframelightsthree = workspace.MainframeLights:GetChildren()
		for i = 1, #mainframelightsthree do
    	mainframelightsthree[i].Light.PointLight.Color = Color3.new(255, 255, 255)
		mainframelightsthree[i].Light.PointLight.Color = Color3.new(255, 255, 255)
		mainframelightsthree[i].Light.BrickColor = BrickColor.new("White")
		end
		end	
	end
end
	end
end
end

while true do
	wait(5)
	print "lol"
	normalTemperature()
	alarmMinor()
	alarmMajor()
end

And this is the error:

21:10:17.277 - Workspace.Meltdown Detector:79: attempt to call global 'normalTemperature' (a nil value)
21:10:17.277 - Stack Begin
21:10:17.277 - Script 'Workspace.Meltdown Detector', Line 79 
21:10:17.278 - Stack End
-- Also line 79 is "normalTemperature()"

I don't know what is wrong. Please help asap! :)

That error occurs when you try to call a function that you haven't defined.

For example:

testFunction()

15:31:01.765 - testFunction():1: attempt to call global 'testFunction' (a nil value)