Dehydrated

This information is sourced from the Sandstorm book.

Dehydration

As the body loses fluids, biological processes begin to break down. This leads to pallor, shaking, nausea, and eventually, a complete collapse of the nervous system. Though dehydration can occur in any environment, the combination of high heat and low humidity typical in waste environments makes it an omnipresent threat there.

As noted on page 304 of the Dungeon Master's Guide, a character must consume 1 gallon of water per day to avoid dehydration. In particularly hot environments (those above 90 degrees F), characters need double the normal amount. The amount of water required to avoid dehydration increases by 1 gallon per temperature band higher than hot (so 3 gallons in severe heat, 4 in extreme heat, and so on). A creature can go without water for a number of hours equal to 24 + its Constitution score. After this time, the creature must make a successful Constitution check each hour (DC 10, +1 for each previous check) or take 1d6 points of nonlethal damage. In particularly hot environments (those above 90 degrees F), the time a creature can go without water before making Constitution checks is reduced.

DEHYDRATION TIMES

Temperature, in degrees F (Band)	Time before Con Checks
90 or lower (warm or cooler)	24 + Con hours
91 to 110 (hot)	12 + Con hours
111 to 140 (severe heat)	6 + Con hours
141 to 180 (extreme heat)	3 + Con hours
181 to 210 (unearthly heat)	Con hours
211 or higher (burning heat)	1/2 Con hours

Being Dehydrated

A lack of sufficient water can cause individuals to become dehydrated - a new condition described here.

Dehydrated: Characters who have taken nonlethal damage from lack of water are considered dehydrated and become fatigued. In addition, if a dehydrated character would take nonlethal damage from hot conditions (such as those described in Sandstorm or on page 303 of the Dungeon Master's Guide), that damage instead becomes lethal damage.

A character who falls unconscious from nonlethal damage due to thirst begins to take the same amount of lethal damage instead. Damage from thirst, whether lethal or nonlethal, cannot be recovered until the character has been treated (see below); not even magic that restores hit points heals this damage.

Treating Dehydration

A character who has taken nonlethal damage from lack of water must be treated with long-term care (see the Heal skill description, page 75 of the Player's Handbook) to recover. This treatment requires 24 hours of care and double the normal amount of water required per day for the conditions (for instance, 2 gallons of water in normal conditions). If the character has also taken lethal damage from lack of water or from a hot environment, add 5 to the Heal DC and double the time required to recover (to 48 hours). Once this Heal check has succeeded, the damage taken by the character can be restored through the normal means.

Alternatively, certain spells can be used to rehydrate a character in place of the recovery time, water, and Heal check. The hydrate spell accomplishes this function, as does the heal spell.