There are no skills associated with Constitution.$^1$
$^1$ Constitution represents a largely passive set of 'skills' which have more to do with enduring than performing a specific action the PC can become proficient in. Therefore, Constitution checks are more uncommon than other ability checks and are usually made without adding a proficiency bonus, although situational bonuses may still apply.
NOTE: An ability check is different from a saving throw; players can be proficient at Constitution saving throws.
$^2$ A PC can only travel for eight hours a day before they risk becoming exhausted.
$^3$ A PC requires one gallon of water per day, or two if the climate is harsh.