Building fires are divided into two classes of severity in NFIRS: “confined fires,” which are those fires confined to certain types of equipment or objects, and “nonconfined fires,” which are not. Confined building fires are small fire incidents that are limited in extent, staying within pots or fireplaces or certain other noncombustible containers.
Confined fires rarely result in serious injury or large content losses, and are expected to have no significant accompanying property losses due to flame damage. Of these two classes, the smaller, confined fires account for the majority of Thanksgiving Day fires in residential buildings at 71 percent. Of these confined fires, cooking is, by far, the predominant type of fire. Nonconfined fires account for the remaining 29 percent of Thanksgiving Day fires in residential buildings.
| Incident Type | Percent |
| Confined fires | 70.9 |
| -Cooking fire, confined to container | 60.6 |
| -Chimney or flue fire, confined to chimney or flue | 5.8 |
| -Incinerator overload or malfunction, fire confined | 0.1 |
| -Fuel burner/boiler malfunction, fire confined | 2.3 |
| -Commercial compactor fire, confined to rubbish | 0.2 |
| -Trash or rubbish fire, contained | 2.0 |
| Nonconfined fires | 29.1 |
| Total | 100.0 |
Although the average number of reported residential building fires on Thanksgiving Day is nearly double that of those on all other days, the average numbers of injuries and dollar loss for all Thanksgiving Day fires in residential buildings are about half those of the same loss measures for non-Thanksgiving Day fires in residential buildings.