How well I remember those "bad-old-day's"......sometimes the SFZ would come into Denver mid-winter with almost all the car's frozen. The carmen would heroically do what they could to restore them, but oftentimes the car's would go out of service, and even entire trains annulled with the passenger's being flown or bussed to their destinations.
Similar problems with A/C in the summers....the individual car units were old and very unreliable....both the axle and engine type generator's prone to failure. Train attendant's carried a supply of cyalume lightsticks
It all came to a head during that notorious winter in the early to midwinter seventies (forgot exact year -- 1976?), when the Chicago hub was in a world of hurt...sending trains down to New Orleans to thaw out. The new HEP Amfleet was pressed into service that it was not intended for--long distance trains....they performed heroically and probably "saved Amtrak" from extinction that year.
