The United Auto Workers on Tuesday warned Detroit's Big Three car makers not to expect any help from the union when it comes to shouldering the burden of mushrooming US health care costs, Reuters reported. The warning, against any attempt to "shift" medical costs onto workers, came from UAW president Ron Gettelfinger, who spoke in a rare news conference ahead of next month's opening of what promises to be tough talks over a new collective labour agreement, the news agency said.