Extreme Climates (PSR Supplement)

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Venturing for hours through inhospitable climates can test a creature’s mettle in ways encounters might not. Typically traveling or working in any such environment forces you to make a DC 10 Constitution save at the end of each phase, and on a failure you lose a Hit Die or suffer some other drawback.

Acclimation. If a creature is “acclimated” to any extreme climate, it never needs to make saves for working in that climate. Creatures encountered in that climate are almost always acclimated to it.

Becoming Acclimated? Some features may specifically grant you acclimiation. Otherwise, your narrator decides whether protags can acclimate to an environment or not. Realistic acclimation would take a month or more, if it’s even possible at all.

Extreme Cold

This includes temperatures well below freezing, such as 0°F or -20°C.

At the end of each phase you spend working or traveling in extreme cold, you must succeed on a DC 10 Constitution save or lose a Hit Die.

You don't need to make this save if any of the following apply:

• You are wearing appropriate cold weather attire over your entire body
• You have resistance or immunity to cold damage.

Extreme Heat

This includes sweltering temperatures, such as above 100°F or 40°C.

At the end of each phase you spend working or traveling in extreme heat, you must succeed on a DC 10 Constitution save or lose a Hit Die.

You don't need to make this save if any of the following apply:

• You were Soaked for at least part of this phase.
• You have resistance or immunity to fire damage.

Miasma

Miasma is an area of patchy foul-colored fog filled, often with flying insects. It is particularly common in swamps or polluted urban areas, and in some cases it can stretch for miles.

At the end of each phase you spend working or traveling in miasma, you must succeed on a DC 10 Constitution save or become Poisoned until you Camp. If already Poisoned this way when you fail this save, you instead lose a Hit Die.

You needn't make this save if any of these apply:

• You have resistance or immunity to poison damage.
• You are immune to the Poisoned condition.

Thin Air

It can be difficult to breathe at high altitudes and in ventilation-deprived caves, among other locations.

At the end of each phase a creature spends working or traveling in thin air, it must succeed on a DC 10 Constitution save or lose a Hit Die.

You needn't make this save if any of these apply:

• You have no need to breathe.
• You are immune to the Suffocating condition
• You can consistently hold your breath for 10 minutes or longer, due to a feature.