"Mean Girls" star Lindsay Lohan (search) was recovering at a hospital after being admitted with a high fever and headache, her publicist said Tuesday.

Lohan, 18, who has been in Los Angeles filming the upcoming movie "Herbie: Fully Loaded," (search) was hospitalized Thursday with a 103-degree fever, publicist Leslie Sloan said.

"She's resting and getting better," Sloan said.

The undisclosed illness forced the actress to postpone taping a cameo role on "That 70's Show," the sitcom that features her boyfriend, Wilmer Valderrama (search).

Production on "Herbie" was also halted and would resume after Lohan recovered, Sloan said.