Source GM Core pg. 98

Often, temperature doesn't impose enough of a mechanical effect to worry about beyond describing the clothing the characters need to wear to be comfortable. Particularly hot and cold weather can make creatures fatigued more quickly during overland travel and can cause damage if harsh enough, as shown in the Temperature Effects table below.

Appropriate cold-weather gear can negate the damage from severe cold or reduce the damage from extreme cold to that of particularly severe cold.

Category

Temperature

Fatigue

Damage

Incredible cold

-80º F or colder (-62º C or colder)

2 hours

4d6 to 6d6 cold every minute

Extreme cold

-79º F to -21º F (-61º C to -29º C)

4 hours

1d6 to 2d6 cold every 10 minutes

Severe cold

-20º F to 12º F (-28º C to -11º C)

4 hours

1d6 to 2d6 cold every hour

Mild cold

13º F to 32º F (-10º C to 0º C)

4 hours

None

Normal

33º F to 94º F (1º C to 34º C)

8 hours

None

Mild heat

95º F* to 104º F* (35º C to 40º C)

4 hours

None

Severe heat

105º F* to 114º F (41º C to 45º C)

4 hours

1d6 to 2d6 fire every hour

Extreme heat

115º F to 139º F (46º C to 59º C)

4 hours

1d6 to 2d6 fire every 10 minutes

Incredible heat

140º F or warmer (60º C or warmer)

2 hours

4d6 to 6d6 fire every minute

  • Adjust temperatures down by 15º F (9º C) in areas of high humidity