Editing v0.31:Temperature

{{quality|Fine|15:51 27 December 2011 (UTC)}}{{av}}

''For temperature as it relates to choosing an embarkation site, see [[Climate]].''

==Temperature scale==
''Dwarf Fortress'' uses its own temperature scale in most cases, often called "Degrees [[Main:Urist|Urist]]" on this wiki.
So if you see something like [HOMEOTHERM:10067], don't be amazed.

For example, [[magma]]'s temperature is 12,000° Urist.

The highest possible temperature in ''Dwarf Fortress'' is 60,000°U - the temperature 60,001°U is used internally for temperatures which have been set to "NONE".

===Conversion===

[DF scale] = [FAHRENHEIT] + 9968

[DF scale] = [CELSIUS] * 9/5 + 10000

[DF scale] = [KELVIN] * 9/5 + 9508.33

[DF scale] = [RANKINE] + 9508.33

''(Note: Mod-makers may find this [http://www.bay12forums.com/smf/index.php?topic=80523.0 Temperature Conversion Utility] handy if they find themselves having to convert a lot of temperatures to and/or from Degrees Urist.)''

===Reference Chart===

{| {{prettytable}}
|- bgcolor="#ddd"
! Significance
! DF Scale
! Fahrenheit
! Celsius
! Kelvin
! Rankine

|-
| Boiling Point of Water
| 10180
| 212
| 100
| 373.15
| 671.67

|-
|Human Body Temperature
| 10066.6<sup>2</sup>
| 98.6
| 37.0
| 310.15
| 558.27

|-
| Freezing Point of Water
| 10000
| 32
| 0
| 273.15
| 491.67

|-
| Absolute Zero
| 9508.33<sup>2</sup>
| -459.67
| −273.15
| 0
| 0

|-
| DF Scale's Zero<sup>1</sup>
| 0
| -9968
| -5555.555...
| -5282.40555...
| -9508.33
|}

<small>
:<sup>1</sup> - Yes, temperatures in Dwarf Fortress can go '''far, far''' below absolute zero, which is physically impossible. Considering Dwarf Fortress also allows [[water wheel#Perpetual motion|perpetual motion]], it's best not to ask questions.
:<sup>2</sup> - Technically, fractional/decimal temperatures are not possible in Dwarf Fortress, as they are stored as unsigned 16-bit integers. For instance, body temp for humans in the raws is rounded to 10067.
</small>

Some general information about temperatures in DF (copied from somewhere on the forums):
{| class="prettytable"
|-
! Event / location
! Temperature
|-
| alcohol freezes
| 9850 U
|-
| water freezes
| 10000 U
|-
| underground
| 10015 U
|-
| outside (varies)
| 10048 U
|-
| dwarf/human body temp
| 10067 U
|-
| floor above magma
| 10075 U
|-
| fat melts
| 10078 U
|-
| water boils
| 10180 U
|-
| fire
| 11000 U
|-
| common stone melts
| 11500 U
|-
| magma
| 12000 U
|-
|}

==Melting point==

This is the temperature at which the material will melt.

==Boiling point==

This is the temperature at which the material will evaporate.

==Ignition point==

This is the temperature at which the material will catch fire.

==Heat damage point==

This is the temperature above which the material will begin to take heat [[wear|damage]]. Burning items without a heat damage point (or with an exceptionally high one) will take damage very slowly, causing them to burn for a very long time (9 months and 16.8 days) before disappearing.

==Cold damage point==

This is the temperature below which the material will begin to take frost [[wear|damage]].

==Specific heat==

This determines how long it takes the material to heat up or cool down. A material with a high specific heat capacity will change temperature more slowly.

==Fixed temperature==

A material's temperature can be forced to always be a certain value via the MAT_FIXED_TEMP [[material definition token]].  The only standard material which uses this is [[nether-cap]] wood, whose temperature is always at the melting point of water.  If a material's temperature is fixed to between its cold damage point and its heat damage point, then items made from that material will never suffer cold/heat damage unless [[dump]]ed into [[magma]] or [[water]].  This makes nether-cap wood [[fire-safe]] and [[magma safe]], in spite of being [[wood]].

The fixed temperature of an item is set when the item comes into existence, so you can't change the MAT_FIXED_TEMP token to cause an existing item to melt/burn/etc.

The fixed temperature of a [[container]] has no effect on its contents, so you can't freeze [[water]] by putting it into a [[bucket]] made from nether cap.

The fixed temperature of a substance only affects items made from that substance.  For example, setting a type of rock to have a fixed temperature over its melting point won't cause walls made from that rock to instantly melt, cause ice walls adjacent to the rock walls to melt, or even cause them to be considered [[warm stone]].
@@ Line 110: / Line 110: @@
 | 10180 U
 |-
-| material is fire-safe
+| fire
 | 11000 U
 |-
 | common stone melts
 | 11500 U
-|-
-| burning coal (max)
-| 11640 U
 |-
 | magma
 | 12000 U
 |-
-| [[titan]]/[[forgotten beast]] fire
-| 14000 U
-|-
-| [[dragon]] fire
-| 50000 U
 |}
@@ Line 155: / Line 147: @@
 ==Fixed temperature==
-A material's temperature can be forced to always be a certain value via the MAT_FIXED_TEMP [[material definition token]].  The only standard material which uses this is [[nether-cap]] wood, whose temperature is always at the melting point of water.  If a material's temperature is fixed to between its cold damage point and its heat damage point, then items made from that material will never suffer cold/heat damage.  This makes nether-caps [[fire-safe]] and [[magma-safe]] despite being a type of [[wood]].
+A material's temperature can be forced to always be a certain value via the MAT_FIXED_TEMP [[material definition token]].  The only standard material which uses this is [[nether-cap]] wood, whose temperature is always at the melting point of water.  If a material's temperature is fixed to between its cold damage point and its heat damage point, then items made from that material will never suffer cold/heat damage unless [[dump]]ed into [[magma]] or [[water]].  This makes nether-cap wood [[fire-safe]] and [[magma safe]], in spite of being [[wood]].
-Due to the way fixed temperature is handled, giving a material a fixed temperature will not cause its actual temperature to change accordingly - instead, its temperature will simply be permanently locked at whatever it was previously. Removing a material's fixed temperature, however, will cause all items made of it to heat or cool until reaching equilibrium with their surroundings.
+The fixed temperature of an item is set when the item comes into existence, so you can't change the MAT_FIXED_TEMP token to cause an existing item to melt/burn/etc.
-The fixed temperature of a [[container]] does affect its contents, but you can't freeze [[water]] by putting it into a [[bucket]] made from nether-cap because water will not freeze until it cools ''below'' {{ct|10000}}.
+The fixed temperature of a [[container]] has no effect on its contents, so you can't freeze [[water]] by putting it into a [[bucket]] made from nether cap.
-The fixed temperature of an inorganic material has no effect on unmined walls made from that material, though boulders '''will''' take on that temperature as they are produced via mining.
+The fixed temperature of a substance only affects items made from that substance.  For example, setting a type of rock to have a fixed temperature over its melting point won't cause walls made from that rock to instantly melt, cause ice walls adjacent to the rock walls to melt, or even cause them to be considered [[warm stone]].