The huge revolutionary thing about the Sotnik and Ratnik programmes before is that it treats all the soldiers gear as one system instead of a collection of separate items that can be used together.
They can develop an outer armoured shell on which they have active camouflage material making the soldier difficult to see or identify, but they also need a heating system as shown above but also they need battery power for their electronic equipment so imagine combining the issues and developing a gel type battery with heating elements inside that can be used for heating or cooling the soldier on station, with the layer of gel being the battery able to store electricity but also absorb impacts to the outer layer.... perhaps a layer inside the battery is not for storing electricity but is a special material that is soft and fluid in normal conditions that goes hard when impacted as an extra hard layer between two gel layers that provide electrical storage for the soldier to operate away from vehicles, but also as a soft trauma layer for use beneath the actual protective layer that stops heavy fast moving bullets and also fragments.
Of course the idea of making soldiers resistant to heavy machine guns will just result in new machine gun rounds likely using flechettes and perhaps more exotic materials like plasma forming HE rounds. Peer enemy troops will likely just start hosing down enemy infantry with 57mm cannon shells or poison gas.
The liquid could include pezio electric crystals that generate a small electric current when crushed or force is applied. So a layer in the sole of the boot or in the leggings could generate a small electric current every step you take... it might not power a radio but it might be enough to power a pair of electrically heated socks to keep your toes from freezing.
Often when you get cold and your core body temperature starts to drop your body struggles to keep your whole body warm... it normally alters your blood circulation to keep your brain and vital organs warm meaning your fingers and toes get reduced warmth, so while a heated vest is a good thing, heated gloves and socks are also important.... most important for soldiers not doing anything... a soldier standing guard will have trouble keeping warm, so a 10 minute burst of these heaters can get their bodies warm and could then be turned down or off while their bodies use the insulation of their clothes to stay warm... wind proof outer layers are essential for this... as is keeping dry.
Obviously critical for battery components to be close to the skin so they don't lose charge in the cold... which would be why a gel battery might be a good idea too as it will be more comfortable as well as shock absorbing.
Any speculation about the meaning of the three buttons on the heating suit. F, B and N seem to be the labels used?