def is_heating_property(prop, prop_wall):
    """Checks whether or not a fluid side is being heated or cooled, from
    a property of the fluid at the wall and the bulk temperature. Returns True 
    for heating the bulk fluid, and False for cooling the bulk fluid.
    
    Parameters
    ----------
    prop : float
        Viscosity (or Prandtl number) of flowing fluid away from the heat
        transfer surface, [Pa*s]
    prop_wall : float
        Viscosity (or Prandtl number) of the fluid at the wall, [Pa*s]

    Returns
    -------
    is_heating : bool
        Whether or not the flow is being heated up by the wall, [-]

    Examples
    --------
    >>> is_heating_property(1E-3, 1.2E-3)
    False
    """
    return prop_wall < prop
