How do you prevent dupes from bringing stuff from the surface into your base?

[Algaernon]

Regolith and Mafic rock have goofy names to separate them from say sand, and other rock species. This helps to disallow surface materials from containers in safe areas of the base. But super-heated iron and granite are also found in the surface biome. In my current game, a Ruby just loaded 100kg of surface iron into the steel smelter. It exploded, releasing high-pressure 230°C steam until half my base was par-boiled.  In the future, I think I'll prevent dupes with the supply task from going outside using door permissions. Is that what you do?

What I would like to do is setup a system so that dupes place the hot iron in a specific container to cool off. Or at least create a partition that prevents them from taking hot materials off the floor and moving them back into the base. So here are some suggestions:

1. There should be a way to set a min-max temperature limit in the filter settings on storage compactors and inputs to crafting buildings (especially smelters!).  Make the default -15° to +60°C maybe? This would be a nice setting to have on build orders too! Dupes must build the building using only materials in the temperature range.
2. There should be a way to set exosuit checkpoints so that they block dupes from carrying items towards the safe side. It will still allow materials out in the direction of the arrow, but nothing comes in from the danger zone. This "quarantine door" idea has been suggested before here and probably many other places.

[InternetGuy]

I did plan to have all of my compactors set to sweep only so that they won't be bringing the hot stuff into the base but then you mentioned iron. That is tricky now I think about it. I think the conveyer system needs a thermo sensor like the pipe and vent thermo sensor and a shut off valve. I think there's a way around this in the game as it is by having conveyers cool off the iron before it gets to your base but that system I have in mind is quite resource intensive and need a lot of planning.

[SharraShimada]

First of all, build all heat intensive buildings outside, or in a sealed bunker.

Materials coming down very hot from the sky (or igneous rock from solidified lava) is best kept beyond the living area.  

Before opening the space-biome, make sure, dupes cant carry in hot materials, and store them outside. 

Be careful with common materials, like iron or granite, because they may be used inside as well for tiles or wires. 

To be safe, build a cooling bunker with automation, disallowing dupes to enter, below a certain temperature. This may cut you off from some ressources for a given time, but the mats are not los, just in cooling storage. 

[Sasza22]

13 hours ago, Algaernon said:

It exploded, releasing high-pressure 230°C steam until half my base was par-boiled.

I`m not actually sure if it was the iron that caused it. Most of the time it happens when the cooling water is too hot. I haven`t had this happen based on the hot iron yet.

Anyway since there`s no way to control the temperature of the stuff dupes bring in there`s a few workarounds. One maentioned already is storing stuff that might get hot outside the base. Another is storing it in your water tanks. Water will cool down the iron pretty fast and since dupes don`t bring too much of it at a time it won`t turn into steam either.

Materials that usually couse problems are iron, dirt (from cooked slime), igneous rock (from volcanoes) and other types of metal if you have a volcano emitting it. Also keep in mind regolith might be used as filtration medium for some of your machines.

[mazeking]

All my inbase storages a "sweep only".
I build bases with modular design. Every module have techincal coridor under it with storages to clean the floor? all corridors a connect to each other and almost all off them isolated.
I cleaned floor directly after i build a new module. I start exploring of new regions by building buffer oxygen zone with storages without "sweep" and doors with limited acess. All regions where could be extremal temperature also have temperature buffer zone with 23 degree waterpool where storages are bounded by doors.
So every new material would be storaged outside of the base in personal storage and every new material that i needed in the base would be deliver to base at 23 degree and desinfected.
And if i don't need a material from that region there would be wild critters that would eat it and excrets materials with their body temperature.