Southwest Airlines Co. warned that costs will climb faster than expected as it grapples with heavy labor expenses, undercutting gains from strong demand for leisure travel.Non-fuel unit costs will rise as much as 9% in the first quarter after an 11% jump in the final months of last year,

Southwest Airlines said Thursday it swung to a fourth-quarter profit of 42 cents a share from a year-ago loss of 42 cents a share, as overall expenses fell on lower fuel costs.

In the midst of the airline’s financial woes, the company just revealed that it will be making some major changes in an effort to cut costs. According to a new report from CNBC, Southwest Airlines is putting a freeze on corporate hiring and promotions.

Southwest Airlines (LVU) put in a solid performance in the fourth quarter and forecast above-consensus revenue per available seat mile for the current quarter as the carrier absorbed surplus capacity across the industry with greater aircraft efficiency and higher airfares.