diff --git a/abms.lua b/abms.lua
index e3c4745..65e9a55 100644
--- a/abms.lua
+++ b/abms.lua
@@ -34,6 +34,7 @@ minetest.register_globalstep(function(dtime)
 		return
 	end
 
+	-- Promote mobs based on spawn position
 	for _, mob in pairs(minetest.luaentities) do
 		if not mob.initial_promotion then
 			local pos = mob.object:getpos()
@@ -54,6 +55,7 @@ minetest.register_globalstep(function(dtime)
 		end
 	end
 
+	-- Spawn mobs in fortresses -- only when a player is near
 	local players = get_connected_players()
 	for i = 1, #players do
 		local player = players[i]
@@ -61,18 +63,6 @@ minetest.register_globalstep(function(dtime)
 		local minp = vector.subtract(pos, 0.5)
 		local maxp = vector.add(pos, 0.5)
 
-		local counts =  find_nodes_in_area(minp, maxp, {"group:surface_hot"})
-		if #counts > 1 then
-			player:set_hp(player:get_hp() - 1)
-		end
-
-		if dps_count % cold_delay == 0 then
-			counts =  find_nodes_in_area(minp, maxp, {"group:surface_cold"})
-			if #counts > 1 then
-				player:set_hp(player:get_hp() - 1)
-			end
-		end
-
 		if dps_count % monster_delay == 0 then
 			local mob_count = 0
 			for _, mob in pairs(minetest.luaentities) do
@@ -105,10 +95,29 @@ minetest.register_globalstep(function(dtime)
 			end
 		end
 
-		-- hunger
-		if dps_count % hunger_delay == 0 then
-			player:set_hp(player:get_hp() - 1)
-			dps_count = hunger_delay
+		if fun_caves.DEBUG and player:get_hp() < 20 then
+			print("HP: "..player:get_hp())
+			player:set_hp(20)
+			return
+		else
+			-- Environmental damage from surfaces/hunger
+			local counts =  find_nodes_in_area(minp, maxp, {"group:surface_hot"})
+			if #counts > 1 then
+				player:set_hp(player:get_hp() - 1)
+			end
+
+			if dps_count % cold_delay == 0 then
+				counts =  find_nodes_in_area(minp, maxp, {"group:surface_cold"})
+				if #counts > 1 then
+					player:set_hp(player:get_hp() - 1)
+				end
+			end
+
+			-- hunger
+			if dps_count % hunger_delay == 0 then
+				player:set_hp(player:get_hp() - 1)
+				dps_count = hunger_delay
+			end
 		end
 	end
 
diff --git a/init.lua b/init.lua
index dfae1f1..ca1a1fe 100644
--- a/init.lua
+++ b/init.lua
@@ -3,6 +3,8 @@ fun_caves.version = "1.0"
 fun_caves.time_factor = 10
 fun_caves.light_max = 8
 fun_caves.path = minetest.get_modpath(minetest.get_current_modname())
+fun_caves.DEBUG = true
+
 
 
 minetest.register_on_mapgen_init(function(mgparams)
diff --git a/mapgen.lua b/mapgen.lua
index 203cf9f..de905f2 100644
--- a/mapgen.lua
+++ b/mapgen.lua
@@ -1,5 +1,3 @@
-local DEBUG = false
-
 local deco_depth = -30  -- place cave stuff this far beneath the surface
 local light_depth = -13  -- depth above which to place corals/sea plants
 local water_level = 1
@@ -169,7 +167,7 @@ fun_caves.is_fortress = function(pos, cs, debug)
 	if debug then
 		print(x, y, z, n, floor((n * 10000) % 19))
 	end
-	if floor((n * 10000) % 19) == 1 or DEBUG then
+	if floor((n * 10000) % 19) == 1 or fun_caves.DEBUG then
 		return true
 	end
 
@@ -235,7 +233,7 @@ local function generate(p_minp, p_maxp, seed)
 									data[ivm] = inner_floor
 								end
 							elseif (z - minp.z) % 5 == 0 or (x - minp.x) % 5 == 0 then
-								--data[ivm] = DEBUG and node["default:glass"] or inner_wall
+								--data[ivm] = fun_caves.DEBUG and node["default:glass"] or inner_wall
 								data[ivm] = inner_wall
 							else
 								data[ivm] = node["air"]
@@ -678,7 +676,7 @@ local function generate(p_minp, p_maxp, seed)
 	if write then
 		vm:set_data(data)
 		--vm:set_param2_data(p2data)
-		if DEBUG then
+		if fun_caves.DEBUG then
 			vm:set_lighting({day = 15, night = 15})
 		else
 			vm:calc_lighting({x=minp.x,y=emin.y,z=minp.z},maxp)
diff --git a/nodes.lua b/nodes.lua
index 3affa0d..4f3b9b8 100644
--- a/nodes.lua
+++ b/nodes.lua
@@ -1,3 +1,12 @@
+local old_is_protected = minetest.is_protected
+function minetest.is_protected(pos, name)
+	local node = minetest.get_node_or_nil(pos)
+	if node and minetest.get_item_group(node.name, "fortress") ~= 0 then
+		return true
+	end
+	return old_is_protected(pos, name)
+end
+
 -- dirt, cave
 local newnode = fun_caves.clone_node("default:dirt")
 newnode.drop = "default:dirt"