def get_cpu_temp() -> float:
    """
    Returns the CPU temperature in Celsius as
    floating point number.

    **This function will only work on the Raspberry Pi platform
    and therefore returns -5 if it's not executed on a Raspberry Pi.**

    :returns: The CPU temperature in percent.
    :rtype: float
    """

    try:
        return float(open("/sys/class/thermal/thermal_zone0/temp").read()) / 1000
    except:
        return -5.0