All employees exposed to traffic in some form, including those as workers and those as flaggers, need to wear an OSHA-approved vest. In this case, the vests approved by OSHA are high-visibility and are ANSI class 2 or 3. Either type of ANSI vest includes a hi-viz yellow mesh background with reflective horizontal and vertical stripes. These stripes go across the chest area and around both shoulders. This way, motorists at all times of day can see roadside workers. If such a vest is too hot, ANSI hi-viz t-shirts are another option, as these shirts have the same combination of stripes.