Cold hand, Warm heart is the fourth material edition for Sword Art Online. It narrates another of the stories Kirito gets involved.
Summary
After a hunting day Kirito returns to his house in Algade, but keeps feeling strange and thinks that it's a new negative status, with a huge effort he manages to reach an inn room and decides to call Klein for help. After typing a desperate message with a blurry vision he sends it and falls unconscious. Hours later, he awakes and hears a voice different from Klein, it was Asuna who was taking care of him and realizes that he sent the message to the wrong person. Asuna takes care of him and tells him that his real body just caught a cold. The next day strangely Asuna is now sick and Kirito is nowhere to be seen, she realizes that Kirito must be training. Then, a portal appears and Kirito emerges from it with a basin with ice, she realized that he made something almost impossible happen; he went to the fifty eighth floor, climbed a mountain, defeated the local boss, which was a dragon, took the ice and returned in less than two hours. For the rest of the day Kirito takes care of her. Asuna then remarks that maybe she could give the cold to him again, and then he could give it back since this sort of situation is not so bad.