diff --git a/assets/mods/basegame/fluid/fluids.csv b/assets/mods/basegame/fluid/fluids.csv
index 74e978137..63abb72d3 100644
--- a/assets/mods/basegame/fluid/fluids.csv
+++ b/assets/mods/basegame/fluid/fluids.csv
@@ -1,4 +1,10 @@
-"id";"name";"shdr";"shdg";"shdb";"shduv";"str";"dsty";"mate";"lumr";"lumg";"lumb";"lumuv";"colour";"vscs";"refl";"tags"
-"1";"BLOCK_WATER";"0.1016";"0.0744";"0.0508";"0.0826";"100";"1000";"WATR";"0.0000";"0.0000";"0.0000";"0.0000";"005599A6";"5";"0.0";"NATURAL"
-"2";"BLOCK_LAVA";"0.1252";"0.1252";"0.1252";"0.1252";"100";"2600";"ROCK"; "0.7664";"0.2032";"0.0000";"0.0000";"FF4600E6";"16";"0.0";"NATURAL,MOLTEN"
-"3";"BLOCK_CRUDE_OIL";"0.1252";"0.1252";"0.1252";"0.1252";"100";"750";"COIL"; "0.0000";"0.0000";"0.0000";"0.0000";"1D0A06F8";"10";"0.0";"NATURAL"
+"id";"name";"shdr";"shdg";"shdb";"shduv";"str";"dsty";"mate";"lumr";"lumg";"lumb";"lumuv";"colour";"vscs";"refl";"tags";"therm"
+"1";"BLOCK_WATER";"0.1016";"0.0744";"0.0508";"0.0826";"100";"1000";"WATR";"0.0000";"0.0000";"0.0000";"0.0000";"005599A6";"5";"0.0";"NATURAL";0
+"2";"BLOCK_LAVA";"0.1252";"0.1252";"0.1252";"0.1252";"100";"2600";"ROCK"; "0.7664";"0.2032";"0.0000";"0.0000";"FF4600E6";"16";"0.0";"NATURAL,MOLTEN";2
+"3";"BLOCK_CRUDE_OIL";"0.1252";"0.1252";"0.1252";"0.1252";"100";"750";"COIL"; "0.0000";"0.0000";"0.0000";"0.0000";"1D0A06F8";"10";"0.0";"NATURAL";1
+
+## therm
+# -1: cryogenic (-100C)
+#  0: room temperature (-10C..10C; e.g. water)
+#  1: hot (100C; e.g. steam, crude oil)
+#  2: molten (1000C; e.g. lava)
diff --git a/assets/mods/basegame/items/itemid.csv b/assets/mods/basegame/items/itemid.csv
index 3f03d9fb9..22baff848 100644
--- a/assets/mods/basegame/items/itemid.csv
+++ b/assets/mods/basegame/items/itemid.csv
@@ -155,7 +155,7 @@ id;classname;tags
 # preferably autogenerated
 # FLUIDSTORAGE: required tag for buckets/canisters
 # OPENSTORAGE: cannot hold gas. Canisters need LIDDEDSTORAGE/SEALEDSTORAGE
-# FLUIDROOMTEMP: cannot hold cryogenic/hot fluids (e.g. lava, steam)
+# NOEXTREMETHERM: cannot hold cryogenic/molten fluids (can only hold fluid with therm 0 or 1)
 # 100000h..1000FFh : container type 0 x Fluid type 0..255
 # 100100h..1001FFh : container type 1 x Fluid type 0..255
 # 100200h..1002FFh : container type 2 x Fluid type 0..255
@@ -164,10 +164,10 @@ id;classname;tags
 # 100500h..1005FFh : container type 5 x Fluid type 0..255
 # ...
 # 10FF00h..10FFFFh : container type 255 x Fluid type 0..255
-1048576;net.torvald.terrarum.modulebasegame.gameitems.ItemBucketWooden00;FLUIDSTORAGE,OPENSTORAGE,FLUIDROOMTEMP,FLUIDSTORAGEEMPTY
-1048577;net.torvald.terrarum.modulebasegame.gameitems.ItemBucketWooden01;FLUIDSTORAGE,OPENSTORAGE,FLUIDROOMTEMP
-#1048578;net.torvald.terrarum.modulebasegame.gameitems.ItemBucketWooden02;FLUIDSTORAGE,OPENSTORAGE,FLUIDROOMTEMP
-1048579;net.torvald.terrarum.modulebasegame.gameitems.ItemBucketWooden03;FLUIDSTORAGE,OPENSTORAGE,FLUIDROOMTEMP
+1048576;net.torvald.terrarum.modulebasegame.gameitems.ItemBucketWooden00;FLUIDSTORAGE,OPENSTORAGE,NOEXTREMETHERM,FLUIDSTORAGEEMPTY
+1048577;net.torvald.terrarum.modulebasegame.gameitems.ItemBucketWooden01;FLUIDSTORAGE,OPENSTORAGE,NOEXTREMETHERM
+#1048578;net.torvald.terrarum.modulebasegame.gameitems.ItemBucketWooden02;FLUIDSTORAGE,OPENSTORAGE,NOEXTREMETHERM
+1048579;net.torvald.terrarum.modulebasegame.gameitems.ItemBucketWooden03;FLUIDSTORAGE,OPENSTORAGE,NOEXTREMETHERM
 
 1048832;net.torvald.terrarum.modulebasegame.gameitems.ItemBucketIron00;FLUIDSTORAGE,OPENSTORAGE,FLUIDSTORAGEEMPTY
 1048833;net.torvald.terrarum.modulebasegame.gameitems.ItemBucketIron01;FLUIDSTORAGE,OPENSTORAGE
diff --git a/src/net/torvald/terrarum/blockproperties/FluidCodex.kt b/src/net/torvald/terrarum/blockproperties/FluidCodex.kt
index c513da291..f224b59b6 100644
--- a/src/net/torvald/terrarum/blockproperties/FluidCodex.kt
+++ b/src/net/torvald/terrarum/blockproperties/FluidCodex.kt
@@ -86,6 +86,8 @@ class FluidCodex {
 
         prop.material = record.get("mate")
 
+        prop.therm = record.intVal("therm")
+
         fluidProps[prop.id] = prop
 
         printdbg(this, "Setting fluid prop ${prop.id} ->>\t${prop.nameKey}")
@@ -126,6 +128,8 @@ class FluidProp {
 
     var reflectance = 0f // the exact colour of the reflected light depends on the texture
 
+    var therm = 0
+
     @Transient var tags = HashSet<String>()
 
 }
\ No newline at end of file
diff --git a/src/net/torvald/terrarum/modulebasegame/gameitems/ItemFluidStorage.kt b/src/net/torvald/terrarum/modulebasegame/gameitems/ItemFluidStorage.kt
index 60cfe2c64..7cb3e1980 100644
--- a/src/net/torvald/terrarum/modulebasegame/gameitems/ItemFluidStorage.kt
+++ b/src/net/torvald/terrarum/modulebasegame/gameitems/ItemFluidStorage.kt
@@ -1,8 +1,6 @@
 package net.torvald.terrarum.modulebasegame.gameitems
 
-import net.torvald.terrarum.BlockCodex
-import net.torvald.terrarum.CommonResourcePool
-import net.torvald.terrarum.INGAME
+import net.torvald.terrarum.*
 import net.torvald.terrarum.blockproperties.Fluid
 import net.torvald.terrarum.gameactors.ActorWithBody
 import net.torvald.terrarum.gameitems.GameItem
@@ -54,6 +52,7 @@ open class ItemFluidStoragePrototype(originalID: ItemID, sheetX: Int, sheetY: In
 
         // empty bucket -> filled bucket
         if (fluid == null) {
+            if (ItemCodex[originalID]!!.hasTag("NOEXTREMETHERM") && FluidCodex[fluidAtWorld.type].therm !in 0..1) return@mouseInInteractableRange -1L
             if (fluidAtWorld.amount < 1f - FLUID_MIN_MASS) return@mouseInInteractableRange -1L
 
             // TODO respect the FLUIDROOMTEMP tag