def hi_to_wbgt(HI):
    """ Convert HI to WBGT using emprical relationship from Bernard and Iheanacho 2015
    WBGT [◦C] = −0.0034 HI2 + 0.96 HI−34; for HI [◦F]
    Args:
        HI = heat index as an array
    """
    
    WBGT = -0.0034*HI**2 + 0.96*HI - 34
    
    return WBGT