Consider a planet similar to Mustafar (of the Star Wars franchise). Ambient temperatures and pressures are nearly 400 Celsius and 80 ATM. A surviving crew of normal humans is running out of resources and is forced to land here.
I am asking this question because no one else has posted one yet. A similar question has been offered about a Venus base here which unfortunately does not concern itself with the species in the colony - they could be aliens. That question also does not help answer the question of resources - it specifically is asking about how advanced this species must be and what technologies they would need.
Because I am dealing only with human physiology, and current technology, this is a new question. I really wish to get a human answer, and avoid alien species and fictional technologies.
They can perform a controlled descent, adapting to pressure changes as they slowly (over days or months?) either glide or float down, but do not have limitless energy resources onboard. They have to somehow adapt to use the nearly limitless geothermal energy of this new home. They will have to scrub or electrolyze their own oxygen from a sulphur, Nitrogen, and CO2, atmosphere and develop a long-term climate control solution. They will have to at first renew but eventually create some sort of agriculture, in some sort of contained enclosures.
- Minerals are abundant, similar to Earth's crust. They must be mined or extracted.
- Water will have to be recycled and eventually produced from elements in the atmosphere.
- Silica (sand) is available to make high-temperature silicone for various applications.
- Unluke Mustafa, there is a thick atmosphere creating very high surface pressures. The mass is roughly earth-like.
- There are mountain ranges however there are also plains and desserts for settlements. No known oceans or lakes exist (except those of lava). If pools or lakes form, they certainly are not aqueous water.
- There is no indigenous life.
- There are no plans to "terraform" the planet. These are essentially Robinson Crusoe survivors needing to adapt to a new world and survive.
- There is no perceptible sunlight on the surface except a dimly glowing sky during "daytime"
- There is no satellite, so no tidal force.
- There are areas available with little to no tectonic activity, and safely distant from volcanoes, but hot just the same. There are no tectonic or volcanic obstacles to habitability if the simply select a good site.
- Combustion engines won't work in the atmosphere, so powered vehicles or aircraft would need to carry all their own propellants and are thus very impractical. Steam power is considered to be the most practical engine.
- Solar radiation is shielded by a magnetosphere. There are no radiation obstacles to habitability.
A good answer identifies in two lists the elements absolutely essential to making the transition from their nearly self-sustaining spaceship with a dwindling energy source to a thriving surface-borne community in an artificial biosphere having only raw mineral resources but limitless energy. The first list is things that absolutely must have been onboard their ship in order to survive and make the transition. The second list is elements, compounds, or conditions which must absolutely exist on the hot planet in order to create their new habitat using the vast geothermal energy available.