All humans have their needs - while some are more important than others, we all need water, food and shelter. Here is a way that I would like to approach them in my OSR games (note that this system is untested and may suck). They assume a slot-based equipment system with ~10 slots per character. Introducing:

Deprivation

Or what happens, when you run out of what you need. Every human-adjacent creature has their needs, which may be un-met during adventuring or other catastrophes. Some of them are simple, like the aforementioned food and water. Others are much more long-term or intangible, like clothing and human contact. If you would recieve exhaustion and you already have a full track, you instead recieve d4 damage. Exhaustion and damage caused by un-met needs may only be fixed if the need is met.

Survival Needs

Temperature

A person who is dressed improperly recieves a slot of exhaustion for every 30 minutes - 10, if they are highly improperly dressed for the weather(this includes nakedness). Clothing that fits the temperatures you are in grants you a +1 bonus on reaction rolls from people who know how to survive in these places.

Clean Water

A person needs ~1 litre of water per day - double if in hot climates. If they recieve half of their required supply of water, mark a slot of exhaustion per day. If they recieve no water, mark a slot of exhaustion per 6 hours. If you drink 2 times the needed amount of water a day, you can ignore the first point of exhaustion in that day.

Food

A person needs 1 ration per day - if they not recieve it, mark an exhaustion slot per every 2 days without food, or 5 days on half-rations. If they ate 2 rations, their injuries regenerate 1.5 times faster.

Safety Needs

Clothing

A person needs three sets of clothing that they regularly wash (if unwashed for a week(or 2 days of labour), dirty clothes give a -1 on all reaction rolls) and to either fix, or exchange them around once every six months. If they can't do either, their clothings are tattered, giving them an extra -1 on reaction rolls and taking up an extra slot (it's hard to pack things up when your pockets have holes in them). Freshly washed clothes grant you a +1 on reaction rolls.

Shelter

A person needs something to protect them from the elements while they sleep. If they spent the last night without any roof over their head (even if it's just a tent) they recieve a -1 penalty on all their checks, as they had trouble sleeping. If you had a proper roof over your head for the last week, you can reroll one failed check during a day.

Freedom from Fear

A person will start to crack if they spend too much time in dangerous places. After a week on the frontlines/in the dungeon they recieve a -1 penalty to all tests until they can spend at least 1 day without needing to stay vigilant. If you spent at least 3 days resting, you have a +1 to all combat checks during the first day you are back on duty.

Social Needs (these are active only if the previous needs are met)

Privacy

A person needs to be able to spend some time alone - if unable to spend at least an hour a week alone (like on a spaceship or the equivalent) they recieve a -1 penalty to all tests. If you have a place which is yours and yours alone, you may reroll a social check once a week.

Meaningful Interactions

They do however also need to have social relationships to avoid going insane. A person who may not honestly talk to another person about their emotions for a week recieves a -4 penalty on checks to hide them, as they spill over. If you do have a confidante whom you can absolutely trust, however, you recieve a +2 bonus on these checks.

A Safe Place

The last need is the hardest one to grasp - a person needs some place that they can truly call home, somewhere they can move to in hard times. There are no penalties for its lack - just a sense of general malaise. If you have one, you may ignore the penalties from an unmet social need once a week.