"Fire" property in random models?

i'm new to roblox studio, so i usually get free models. sometimes those models have something called "fire", with the fire icon. in it, is a script called "spread". the only thing in there is just coding that doesn't look like a virus' coding. when i test run the game in roblox studio, the model doesn't do anything. code: function Spread(part) check = part:findFirstChild("Fire") if check == nil then script.Parent:Clone().Parent = part

	elseif check ~= nil then
check.Size = check.Size + 1000000
check.Heat = check.Heat  +1000000
end

end

script.Parent.Parent.Touched:connect(Spread)

i don't really have an idea what that code means, but it doesn't look suspicious. i'm just wondering whether or not the model is okay to use.