An INFJ who is focusing inwardly on their impressions and thoughts probably does appear cold and distant, especially to SF types. I have been told that I have resting bitch face and that I look mean and scary. Gentler folks ask if I am tired or sick. I have learned that the best antidote to this is to get my head out of the zone and pretend to actually be present. It is difficult, but I try hard to smile and be attentive, even when I am in boring meetings with annoying people that make me want to rip my hair out...
Most of the INFPs that I know are like kittens. They might arch their backs and hiss and spit, but they are never scary and seldom cold. If they get mad, it seldom lasts long. But there is nothing colder than when an INFJ has had enough. Which is why they are famous for the "door slam". Even if not mad, there is this faraway stare thing when we look right through something or someone without seeing... because our minds are completely absorbed in something complex.
Ni and Ti are cold and detached. Fe is warm.