The margin a young bird has, an old one does not
A young, fit bird is a small furnace: fast metabolism, good circulation, full feathering, and the muscle to shiver and flutter his way warm again after a chill. An old bird runs the same systems with worn parts. His metabolism ticks over more slowly, his circulation reaches his feet and skin less efficiently, his feathers may be thinner, and he has less muscle and fat in reserve. The result is that the temperature swings and stray breezes a young bird barely notices become real energetic costs for him — and a bird spending his budget on staying warm has less left for appetite, activity, and fighting off the ordinary germs of a household.
Steadiness beats warmth
The precaution that matters most is not a higher temperature but a level one. Keep his room in the comfortable range he is already used to, and defend it around the clock: the classic failure is a house that is warm while people are up and drops sharply once the heating rests overnight, leaving the bird coldest at the hour he is least active. A thermostat-controlled heater in his room, positioned so it never blows directly across the cage, smooths out that dip. Sudden changes in either direction are the enemy — carrying him from a warm room into a cold one for cage cleaning, or parking the cage beside a frequently opened exterior door in winter, asks his body to adjust at a speed it no longer manages. When a move between temperatures is unavoidable, stage it gradually and watch him for fluffing, shivering, or going quiet, which are his ways of saying the change was too fast.
Draft control, taken seriously
A draft is moving air, and to a small old bird it strips heat like wind over skin. Audit his cage position the way a draft would travel: not beside doors that open all day, not in the line between a window and a hallway, not under or in front of heating and cooling vents, and not against an outside wall that turns cold at night. Hold the back of your hand at cage height in the spots you suspect; if you can feel air moving while the room seems still, so can he. A cage cover at night and a solid-backed sleep cage cut the remaining risk, and in cold weather check the actual temperature at cage height rather than trusting the household thermostat on the wall across the room, since warm air rises and his corner can be several degrees cooler than the reading.
The hot side of the same problem
Old birds overheat less gracefully, too — a cage in direct sun through a window, or a room that climbs fast on a warm day, can leave him panting and holding his wings away from his body with no reserves to cope. Give him a shaded end of the cage to retreat to, fresh water he can reach without a climb, and the same steadiness rule: no sharp swings. Put the simple daily rhythm into practice — a morning and evening check of his room's warmth, his position, and how he is sitting — and share those checks in KinsLe Care Teams so whoever is first up or last to bed confirms the old bird's corner is exactly as it should be.