There is no crew-accessible PA volume control on the airplane. The F/As, at least, can hear how loud the announcement is and adjust how loudly they speak. Us pilots can't hear the PA so don't know if we're too loud or too soft.

The temperature control on all 737s, except the 737-700, is in three zones; Flight deck, front half, and back half. The 737-700 has only two zones, flight deck and cabin.

I am constantly asking the F/As how the temperature is. The most common answer I receive is "no complaints". Please "complain" if the temperature is uncomfortable so that we'll get the message and can adjust it.

I've had good luck with temperature control in the MAX aircraft. It's newer and seems to work better. Of course, that assumes that the temperature selector is set to the correct temperature. A warmer temperature must be set on a flight with a low passenger load and a cooler temperature set of a full(-sh) flight. It doesn't show up the temperature that is selected, however, so there is some trial and error.

Please tell an F/A when you are uncomfortable. I can't fix it if I don't know.