Nikolai didn’t move a lot in his sleep, he might toss or turn a few times throughout the night but thats it. You on the other hand toss and turn all night in your sleep like its a crime to stay sleeping in one position for long. Nikolai was used to this though, it didn’t really bother him. So one night when you hadn’t kicked him or tossed and turned much he was a bit concerned. Until he felt your forehead and realized you had a fever. He pulled you close as you slept, not caring if he got sick