A narrower band, held steady, for a Shih Tzu
A Shih Tzu kept indoors does best in a steady 66 to 74 degrees Fahrenheit. The range itself looks ordinary, but the reason for holding it carefully is specific to this breed. A Shih Tzu has a short, flat face, and that shortened airway makes the panting mechanism every dog relies on noticeably less efficient. A long-nosed dog can compensate for a warm room by panting harder; a Shih Tzu reaches the limit of that strategy sooner. At the cold end, a Shih Tzu is also a small dog, often kept in a short clip, who can chill on a cold floor in an over-cooled room. Steady, moderate and monitored is the correct approach, with the dog's resting breathing as your daily instrument.
Breathing is the Shih Tzu's thermometer
Breathing tells you more than the thermostat with a Shih Tzu. At a comfortable temperature, a resting Shih Tzu breathes quietly through his nose with only the soft sounds normal for the breed. As a room warms, the breathing becomes audible, then laboured: mouth open, tongue out, sides working, and a dog who cannot settle into sleep. Snoring that is much louder than his usual, in a warm room, belongs on the same warning list. Learn his baseline on a cool, comfortable evening so you can recognise the change early on a hot one. If a Shih Tzu's breathing at rest stays effortful after you have cooled the room, moved him to shade and offered water, contact a veterinarian promptly, because flat-faced dogs can deteriorate quickly once cooling falls behind.
Coat, sunrooms and sleeping arrangements
Coat and room choice interact strongly in a Shih Tzu. A Shih Tzu in a long, flowing coat carries real insulation and will prefer the cooler half of the band, while a puppy-cut Shih Tzu handles warmth slightly better and cold slightly worse. Sunrooms and conservatories are the highest-risk indoor spaces for this breed, heating fast and trapping humid air; a Shih Tzu should not nap unsupervised in one on a bright day. At night, place his bed in the room with the most stable temperature rather than the warmest, keep a fan circulating air without blasting him directly, and make sure water is reachable without a trip through a warm hallway. After any exertion, even an excited play session indoors, let him recover in the coolest room before bed.
Why the whole household must know his limit
The whole household must know a Shih Tzu's limit because the danger scenario is usually a kind person doing something ordinary: closing him in a warm bedroom for a nap, dressing him in a sweater indoors for a photograph and forgetting it, or letting him follow the sun patch all afternoon. Written guidance prevents all three. Note his band, the instruction to judge by resting breathing, and the rule that a sweater is for outdoors only. When everyone in the home shares that understanding, his environment stays inside the narrow zone his airway requires, and KinsLe Family Sharing keeps those exact Shih Tzu notes on his profile where any family member can check them before changing his routine.