# Red Dragon ## Regional effects _Source: Monster Manual (2024)_ The region containing an adult or ancient red dragon's lair is warped by its presence, creating the following effects: - **Burning Heat.** The area within 1 mile of the lair is an area of extreme heat. A burning creature or object takes an additional `1d4` Fire damage at the start of each of its turns. - **Smoldering Haze.** The area within 1 mile of the lair is [Lightly Obscured](3-Mechanics/CLI/rules/variant-rules/lightly-obscured-xphb.md) with clouds of ash. Whenever a creature other than the dragon or one of its allies finishes a [Long Rest](3-Mechanics/CLI/rules/variant-rules/long-rest-xphb.md) in that area, that creature must succeed on a DC 15 Constitution saving throw or have the [Poisoned](3-Mechanics/CLI/rules/conditions.md#Poisoned) condition for 1 hour. If the dragon dies or moves its lair elsewhere, these effects end immediately.