Compress-space is bad for humans

Terrestrial organisms are built for a particular level of atmospheric pressure, a particular gravity. Spending time outside of these conditions has known, documented effects on the body, almost all of them detrimental. The same goes for spacetime. Our bodies evolved in conditions where time passes through us in one direction, at a set rate, and space is predictably navigable. Disrupting these patterns changes a body in ways akin to rising too fast after a dive. It can easily become deadly. This is precisely why the Wishrat Canals aren’t open to human visitors, normally. They make heavy use of compress-space. Without proper preparation and flexibility, even a few minutes traversing the web will induce in you horrible bends.
  The situation isn’t hopeless, though. For times when a non-wishrat needs to enter the canals (most frequently, because a human child fell down a well and can only get out via the wellevator in the central city, Spider’s Eye), there are tools that can help. If the transient has time, they can undergo training to become increasingly tolerant with spacetime fluctuations. This typically takes a few weeks to complete. A creature that hasn’t been engineered to traverse these lines, as Indigo are, still won’t feel quite comfortable in compress-space. But they can do it.
  For emergency situations, there’s another tool: indigo, the plant our guys are named for. Indigofera tempora naturally possesses the ability to coexist with and even manipulate spacio-temporal fields, giving it a unique ecological niche. Animals who eat the plant can “borrow its powers” for a short time, becoming temporarily more tolerant of the fields. Ingesting the plant also induces an altered mental state much like being drunk or high. It’s likely the two phenomena are linked, like someone being more loose and resistant to collision damage when under the influence. Indigo who visit from beyond the wells and don’t have the time for temporal training will often eat tempora; though they could survive compress-space without it, the temporal high makes the journey more pleasant.
  Incidentally, this is precisely the way they handle it when an adult human falls down a well and needs a hospital ASAP in the story I’m planning for this world.