Nearly 150 students of an aided upper primary school at Koilady in this north Kerala district are undergoing treatment for fever and vomiting over the last three days, official said.The children are students of the Mar Baselios Aided Upper Primary School and of them 38, who continued to show discomfort, have been admitted to the Bathery Taluk hospital, they said.The District Medical Officer (DMO) said that there was currently no need to be worried and that as a precautionary measure, a week-long holiday has been declared for the school.A special ward has been set up at the Bathery Taluk hospital for the treatment of the children, the official said.Apart from the students, a teacher at the school has also reported physical discomfort, the DMO said.Panchayat officials who visited the hospital stated that the current health condition of the children was satisfactory.They said that some children had started showing symptoms since June 1, but the exact cause for their physical discomfort has not yet been confirmed.The doctors said that the Health Department had collected samples and sent them for testing to know the reasons behind the children’s discomfort.