We went to Cinnabar on 7/2 at 6 p.m. for pre-theater dinner. The restaurant has recently opened and is located at 235 W 56th St @ 8th Ave.
When the first two in our party walked in, they noticed that it was a bit too warm. They mentioned it to the hostess who said the A/C was working and that it would soon cool down. We had a drink and dim sum at the bar. The dim sum was all right; the dumplings and egg rolls were nice, although not particularly special. We ordered a ginger ale cold, but w/o ice and it was served correctly.
The good times ended, however, when, soon after, the remainder of our party joined soon after. We were brought to our table and it felt like we were entering a very hot sauna. The hostess -- agreeing that it was uncomfortably hot -- offered to re-seat us, but noted that all of the tables were the same temperature. (Notably, the place was mostly empty. There was one other couple dining and two people sitting at the bar.)
We ordered appetizers, but never got to eat them as it remained far too hot to enjoy ourselves. After we requested a fan, the waitress jokingly noted that if she had a fan, she would be using it herself. (Positive note: the server and bartender were understanding and refreshingly honest about the heat.) When one member of our party began to visibly sweat through his shirt, we walked out. Outside, where it was in high 80s or low 90s, it felt cooler by comparison. (We went across the street to Patsy's for a traditional Italian meal.)
Find out about the A/C before you go. A review on Cityseach indicates that another diner had the same problem as we did a few nights prior and the restaurant staff told us that the A/C is not broken. Meaning it won't improve? Might be best to hold off til Winter.