Temperature is the variable that decides whether a nuru session works, and it is the one most often mishandled. The gel cools faster than oil, and a cooling gel quietly undoes everything the technique is built on.
If you were allowed to get one thing right in a nuru session and had to concede the rest, it would be heat. Not pressure, not technique, not duration. Heat. The whole method assumes a continuous warm film between two bodies, and a film that has dropped below skin temperature stops being a medium and starts being a distraction — the body registers it as wet rather than as warm, and the state the technique is trying to produce does not arrive.
Because it is mostly water. Water has a high heat capacity, which is why the gel holds warmth well once it has it, but it also conducts heat away readily to anything cooler than itself, which is why it loses warmth quickly to a cold room, a cold sheet or cold skin. Oil is worse at holding heat but better at seeming warm, since a thin film of it takes skin temperature almost immediately and stays there. The gel is a thick layer with real mass, and a thick layer takes time to reach equilibrium. Left alone in a cool room it will find room temperature and stay there.
So the management of heat in a session is not one action. It is a sequence of small ones, and each covers a different leak.
A little above body heat is the target, and the reason the margin is small is that warm and hot produce opposite results. Gel that is genuinely hot is startling on contact, it makes the recipient tense at exactly the moment they should be settling, and it cools through the pleasant range too quickly on its way down. The correct temperature is one that is not noticed as a temperature. You should register weight and movement, and the warmth should be something you only become aware of afterwards, when the room feels cooler than it did.
The rewarming mid-session is the part that distinguishes careful work from careless work, and it is a small logistical problem rather than a mysterious skill. It has to be done without breaking contact for longer than a few seconds, because the continuity is the technique, and the therapists who are good at it have worked out their own way of doing it in the rooms they usually work in.
It means a room that can be made warm is worth more to the session than a room that is large or well appointed. An apartment with decent heating beats a beautiful room with a draught. A bathroom with reliable hot water matters at both ends of the hour. None of this requires anything special — most rooms in the city manage all of it — but it is worth a thought when you are choosing where to be, and it is worth mentioning when you book if you already know the heating is unreliable.
It also explains something that surprises people about the aftermath. The sense of warmth from a full-length nuru session tends to persist for hours, longer than the equivalent from a hands-and-oil session, because what has been done is not a local stimulation of one area but a slow warming of most of the body's surface for an extended period. That is a heat effect, not a massage effect, and it is the clearest evidence that the temperature work was done properly.