diff --git a/data/json/furniture_and_terrain/terrain-fences-gates.json b/data/json/furniture_and_terrain/terrain-fences-gates.json
index c91d5d3a8f12e..ebf7919e98c47 100644
--- a/data/json/furniture_and_terrain/terrain-fences-gates.json
+++ b/data/json/furniture_and_terrain/terrain-fences-gates.json
@@ -31,7 +31,7 @@
     "move_cost": 2,
     "connect_groups": "WALL",
     "connects_to": "WALL",
-    "flags": [ "TRANSPARENT", "FLAMMABLE", "FLAT", "BURROWABLE" ],
+    "flags": [ "TRANSPARENT", "FLAMMABLE", "FLAT", "BURROWABLE", "PERMEABLE" ],
     "bash": {
       "str_min": 6,
       "str_max": 150,
@@ -152,7 +152,7 @@
     "symbol": ".",
     "color": "cyan",
     "move_cost": 2,
-    "flags": [ "TRANSPARENT", "FLAT", "ROAD", "BURROWABLE" ],
+    "flags": [ "TRANSPARENT", "FLAT", "ROAD", "BURROWABLE", "PERMEABLE" ],
     "connect_groups": "CHAINFENCE",
     "connects_to": "CHAINFENCE",
     "close": "t_chaingate_c",
@@ -267,7 +267,7 @@
     "symbol": ".",
     "color": "cyan",
     "move_cost": 2,
-    "flags": [ "TRANSPARENT", "FLAT", "ROAD" ],
+    "flags": [ "TRANSPARENT", "FLAT", "ROAD", "PERMEABLE" ],
     "connect_groups": "WALL",
     "connects_to": "WALL",
     "close": "t_retractable_gate_c",
@@ -294,7 +294,7 @@
     "move_cost": 3,
     "coverage": 60,
     "rotates_to": "INDOORFLOOR",
-    "flags": [ "TRANSPARENT", "FLAMMABLE_ASH", "DOOR", "MOUNTABLE", "BURROWABLE" ],
+    "flags": [ "TRANSPARENT", "FLAMMABLE_ASH", "DOOR", "MOUNTABLE", "BURROWABLE", "PERMEABLE" ],
     "connect_groups": "WOODFENCE",
     "connects_to": "WOODFENCE",
     "open": "t_fencegate_o",
@@ -331,7 +331,7 @@
     "symbol": ".",
     "color": "brown",
     "move_cost": 2,
-    "flags": [ "TRANSPARENT", "FLAMMABLE_ASH", "FLAT", "ROAD", "BURROWABLE" ],
+    "flags": [ "TRANSPARENT", "FLAMMABLE_ASH", "FLAT", "ROAD", "BURROWABLE", "PERMEABLE" ],
     "connect_groups": "WOODFENCE",
     "connects_to": "WOODFENCE",
     "close": "t_fencegate_c",
@@ -480,7 +480,7 @@
     "color": "brown",
     "looks_like": "t_chaingate_o",
     "move_cost": 2,
-    "flags": [ "TRANSPARENT", "FLAT", "ROAD", "BURROWABLE" ],
+    "flags": [ "TRANSPARENT", "FLAT", "ROAD", "BURROWABLE", "PERMEABLE" ],
     "connect_groups": "CHAINFENCE",
     "connects_to": "CHAINFENCE",
     "close": "t_chickenwire_gate_c",
@@ -524,7 +524,8 @@
       "MOUNTABLE",
       "SHORT",
       "AUTO_WALL_SYMBOL",
-      "BURROWABLE"
+      "BURROWABLE",
+      "PERMEABLE"
     ],
     "connect_groups": "WOODFENCE",
     "connects_to": "WOODFENCE",
@@ -589,7 +590,7 @@
     "color": "brown",
     "looks_like": "t_fence_post",
     "move_cost": 2,
-    "flags": [ "TRANSPARENT", "THIN_OBSTACLE", "SHORT" ],
+    "flags": [ "TRANSPARENT", "THIN_OBSTACLE", "SHORT", "PERMEABLE" ],
     "bash": {
       "str_min": 4,
       "str_max": 20,
@@ -651,7 +652,7 @@
       "message": "You finish cutting the metal.",
       "byproducts": [ { "item": "pipe", "count": 6 } ]
     },
-    "flags": [ "TRANSPARENT", "THIN_OBSTACLE" ],
+    "flags": [ "TRANSPARENT", "THIN_OBSTACLE", "PERMEABLE" ],
     "oxytorch": { "result": "t_dirt", "duration": "1 seconds", "byproducts": [ { "item": "pipe", "count": [ 1, 4 ] } ] },
     "bash": {
       "str_min": 8,
@@ -728,7 +729,7 @@
     "color": "brown",
     "looks_like": "t_fence_post",
     "move_cost": 2,
-    "flags": [ "TRANSPARENT", "THIN_OBSTACLE" ],
+    "flags": [ "TRANSPARENT", "THIN_OBSTACLE", "PERMEABLE" ],
     "deconstruct": { "ter_set": "t_dirt", "items": [ { "item": "2x4", "count": 2 } ] },
     "bash": {
       "str_min": 8,
@@ -766,7 +767,7 @@
     "symbol": "$",
     "color": "blue",
     "move_cost": 4,
-    "flags": [ "TRANSPARENT", "THIN_OBSTACLE", "SHORT", "EASY_DECONSTRUCT", "BURROWABLE" ],
+    "flags": [ "TRANSPARENT", "THIN_OBSTACLE", "SHORT", "EASY_DECONSTRUCT", "BURROWABLE", "PERMEABLE" ],
     "deconstruct": { "ter_set": "t_fence_post", "items": [ { "item": "lc_wire", "count": 2 } ] },
     "boltcut": {
       "result": "t_fence_post",
@@ -797,7 +798,7 @@
       "sound": "Snick, snick, gachunk!",
       "byproducts": [ { "item": "wire_barbed", "count": 2 } ]
     },
-    "flags": [ "TRANSPARENT", "SHARP", "THIN_OBSTACLE", "SHORT", "EASY_DECONSTRUCT", "BURROWABLE" ],
+    "flags": [ "TRANSPARENT", "SHARP", "THIN_OBSTACLE", "SHORT", "EASY_DECONSTRUCT", "BURROWABLE", "PERMEABLE" ],
     "deconstruct": { "ter_set": "t_fence_post", "items": [ { "item": "wire_barbed", "count": 2 } ] },
     "bash": {
       "str_min": 8,
@@ -816,7 +817,7 @@
     "symbol": "$",
     "color": "brown",
     "move_cost": 3,
-    "flags": [ "TRANSPARENT", "THIN_OBSTACLE", "EASY_DECONSTRUCT", "BURROWABLE" ],
+    "flags": [ "TRANSPARENT", "THIN_OBSTACLE", "EASY_DECONSTRUCT", "BURROWABLE", "PERMEABLE" ],
     "deconstruct": { "ter_set": "t_fence_post", "items": [ { "item": "rope_6", "count": 2 } ] },
     "bash": {
       "str_min": 8,
@@ -874,7 +875,7 @@
     "move_cost": 0,
     "coverage": 60,
     "rotates_to": "INDOORFLOOR",
-    "flags": [ "TRANSPARENT", "FLAMMABLE_ASH", "DOOR", "BURROWABLE" ],
+    "flags": [ "TRANSPARENT", "FLAMMABLE_ASH", "DOOR", "BURROWABLE", "PERMEABLE" ],
     "connect_groups": "WOODFENCE",
     "connects_to": "WOODFENCE",
     "open": "t_splitrail_fencegate_o",
@@ -912,7 +913,7 @@
     "color": "brown",
     "looks_like": "t_fencegate_o",
     "move_cost": 2,
-    "flags": [ "TRANSPARENT", "FLAMMABLE_ASH", "FLAT", "ROAD", "BURROWABLE" ],
+    "flags": [ "TRANSPARENT", "FLAMMABLE_ASH", "FLAT", "ROAD", "BURROWABLE", "PERMEABLE" ],
     "connect_groups": "WOODFENCE",
     "connects_to": "WOODFENCE",
     "close": "t_splitrail_fencegate_c",
@@ -988,7 +989,7 @@
     "move_cost": 0,
     "coverage": 60,
     "rotates_to": "INDOORFLOOR",
-    "flags": [ "TRANSPARENT", "DOOR", "BURROWABLE" ],
+    "flags": [ "TRANSPARENT", "DOOR", "BURROWABLE", "PERMEABLE" ],
     "connect_groups": "WOODFENCE",
     "connects_to": "WOODFENCE",
     "open": "t_gate_metal_o",
@@ -1028,7 +1029,7 @@
     "looks_like": "t_fencegate_o",
     "move_cost": 2,
     "coverage": 60,
-    "flags": [ "TRANSPARENT", "BURROWABLE", "FLAT", "ROAD" ],
+    "flags": [ "TRANSPARENT", "BURROWABLE", "FLAT", "ROAD", "PERMEABLE" ],
     "connect_groups": "WOODFENCE",
     "connects_to": "WOODFENCE",
     "close": "t_gate_metal_c",
@@ -1092,7 +1093,7 @@
     "move_cost": 0,
     "coverage": 60,
     "rotates_to": "INDOORFLOOR",
-    "flags": [ "FLAMMABLE_ASH", "DOOR", "BURROWABLE" ],
+    "flags": [ "FLAMMABLE_ASH", "DOOR", "BURROWABLE", "PERMEABLE" ],
     "connect_groups": "WOODFENCE",
     "connects_to": "WOODFENCE",
     "open": "t_privacy_fencegate_o",
@@ -1130,7 +1131,7 @@
     "color": "brown",
     "looks_like": "t_fencegate_o",
     "move_cost": 2,
-    "flags": [ "FLAMMABLE_ASH", "FLAT", "ROAD", "BURROWABLE", "TRANSPARENT" ],
+    "flags": [ "FLAMMABLE_ASH", "FLAT", "ROAD", "BURROWABLE", "TRANSPARENT", "PERMEABLE" ],
     "connect_groups": "WOODFENCE",
     "connects_to": "WOODFENCE",
     "close": "t_privacy_fencegate_c",
@@ -1167,7 +1168,17 @@
     "symbol": "#",
     "color": "yellow",
     "move_cost": 3,
-    "flags": [ "FLAMMABLE_ASH", "TRANSPARENT", "NOITEM", "THIN_OBSTACLE", "MOUNTABLE", "SHORT", "AUTO_WALL_SYMBOL", "BURROWABLE" ],
+    "flags": [
+      "FLAMMABLE_ASH",
+      "TRANSPARENT",
+      "NOITEM",
+      "THIN_OBSTACLE",
+      "MOUNTABLE",
+      "SHORT",
+      "AUTO_WALL_SYMBOL",
+      "BURROWABLE",
+      "PERMEABLE"
+    ],
     "connect_groups": "RAILING",
     "connects_to": "RAILING",
     "bash": {
@@ -1192,7 +1203,7 @@
     "symbol": "#",
     "color": "cyan",
     "move_cost": 3,
-    "flags": [ "TRANSPARENT", "NOITEM", "THIN_OBSTACLE", "MOUNTABLE", "SHORT", "AUTO_WALL_SYMBOL", "BURROWABLE" ],
+    "flags": [ "TRANSPARENT", "NOITEM", "THIN_OBSTACLE", "MOUNTABLE", "SHORT", "AUTO_WALL_SYMBOL", "BURROWABLE", "PERMEABLE" ],
     "connect_groups": "RAILING",
     "connects_to": "RAILING",
     "deconstruct": { "ter_set": "t_rock_floor", "items": [ { "item": "glass_sheet", "count": 2 }, { "item": "pipe", "count": 4 } ] },
@@ -1217,7 +1228,7 @@
     "symbol": "#",
     "color": "dark_gray",
     "move_cost": 3,
-    "flags": [ "TRANSPARENT", "NOITEM", "THIN_OBSTACLE", "MOUNTABLE", "SHORT", "AUTO_WALL_SYMBOL", "BURROWABLE" ],
+    "flags": [ "TRANSPARENT", "NOITEM", "THIN_OBSTACLE", "MOUNTABLE", "SHORT", "AUTO_WALL_SYMBOL", "BURROWABLE", "PERMEABLE" ],
     "connect_groups": "RAILING",
     "connects_to": "RAILING",
     "deconstruct": { "ter_set": "t_rock_floor", "items": [ { "item": "sheet_metal", "count": 2 }, { "item": "pipe", "count": 4 } ] },
@@ -1243,7 +1254,17 @@
     "color": "cyan",
     "looks_like": "t_ponywall",
     "move_cost": 3,
-    "flags": [ "TRANSPARENT", "NOITEM", "THIN_OBSTACLE", "MOUNTABLE", "SHORT", "AUTO_WALL_SYMBOL", "MINEABLE", "BURROWABLE" ],
+    "flags": [
+      "TRANSPARENT",
+      "NOITEM",
+      "THIN_OBSTACLE",
+      "MOUNTABLE",
+      "SHORT",
+      "AUTO_WALL_SYMBOL",
+      "MINEABLE",
+      "BURROWABLE",
+      "PERMEABLE"
+    ],
     "connect_groups": "RAILING",
     "connects_to": "RAILING",
     "bash": {
@@ -1268,7 +1289,7 @@
     "color": "light_gray",
     "looks_like": "t_guardrail_bg_dp",
     "move_cost": 3,
-    "flags": [ "TRANSPARENT", "NOITEM", "REDUCE_SCENT", "MOUNTABLE", "SHORT", "THIN_OBSTACLE", "ROAD", "BURROWABLE" ],
+    "flags": [ "TRANSPARENT", "NOITEM", "REDUCE_SCENT", "MOUNTABLE", "SHORT", "THIN_OBSTACLE", "ROAD", "BURROWABLE", "PERMEABLE" ],
     "bash": {
       "str_min": 8,
       "str_max": 150,
@@ -1286,7 +1307,7 @@
     "symbol": "#",
     "color": "light_gray",
     "move_cost": 3,
-    "flags": [ "TRANSPARENT", "NOITEM", "REDUCE_SCENT", "MOUNTABLE", "SHORT", "THIN_OBSTACLE", "ROAD", "BURROWABLE" ],
+    "flags": [ "TRANSPARENT", "NOITEM", "REDUCE_SCENT", "MOUNTABLE", "SHORT", "THIN_OBSTACLE", "ROAD", "BURROWABLE", "PERMEABLE" ],
     "bash": {
       "str_min": 8,
       "str_max": 150,
@@ -1304,7 +1325,7 @@
     "symbol": "#",
     "color": "light_gray",
     "move_cost": 3,
-    "flags": [ "TRANSPARENT", "NOITEM", "REDUCE_SCENT", "MOUNTABLE", "SHORT", "THIN_OBSTACLE", "ROAD", "BURROWABLE" ],
+    "flags": [ "TRANSPARENT", "NOITEM", "REDUCE_SCENT", "MOUNTABLE", "SHORT", "THIN_OBSTACLE", "ROAD", "BURROWABLE", "PERMEABLE" ],
     "looks_like": "t_guardrail_bg_dp",
     "bash": {
       "str_min": 8,
@@ -1325,7 +1346,7 @@
     "looks_like": "t_metal_railing",
     "move_cost": 0,
     "examine_action": "chainfence",
-    "flags": [ "TRANSPARENT", "THIN_OBSTACLE", "MOUNTABLE", "CLIMBABLE", "AUTO_WALL_SYMBOL", "BURROWABLE" ],
+    "flags": [ "TRANSPARENT", "THIN_OBSTACLE", "MOUNTABLE", "CLIMBABLE", "AUTO_WALL_SYMBOL", "BURROWABLE", "PERMEABLE" ],
     "connect_groups": "RAILING",
     "connects_to": "RAILING",
     "deconstruct": { "ter_set": "t_dirt", "items": [ { "item": "sheet_metal", "count": 4 }, { "item": "pipe", "count": 2 } ] },
diff --git a/src/game.cpp b/src/game.cpp
index babfd49446c8e..1055e1867b919 100644
--- a/src/game.cpp
+++ b/src/game.cpp
@@ -1711,7 +1711,14 @@ units::temperature_delta get_heat_radiation( const tripoint_bub_ms &location )
             continue;
         }
         if( player_character.pos_bub() == location ) {
-            if( !here.clear_path( dest, location, -1, 1, 100 ) ) {
+            bool heat_can_spread = true;
+            for( const tripoint_bub_ms &p : line_to( player_character.pos_bub(), dest ) ) {
+                if( !here.has_flag( ter_furn_flag::TFLAG_PERMEABLE, p ) && here.impassable( p ) ) {
+                    heat_can_spread = false;
+                    break;
+                }
+            }
+            if( !heat_can_spread ) {
                 continue;
             }
         } else if( !here.sees( location, dest, -1 ) ) {