When you consider feng shui you must look at the surroundings which include the arrangement of living space, the neighbourhood, the city or town we live in, and the geographical area. If you are applying the thermal energy theory to tea you have to first decide if these environments are cold (yin) in nature or warm (yang) in nature then drink tea with the opposite thermal energy in an attempt to create harmony.
If you live in a generally cold climate (like most of Canada and England) you should drink more tea with warm thermal nature. If you live in a generally warm climate (like the Southern USA and most of China) you should drink more tea with a cool thermal nature.
As far as your living space is concerned, you should drink tea with warm properties if your suite is always cold, is below ground, is not well lit with natural light, or faces West or North- has yin properties. Conversely, you should drink tea with cool properties if your suite is always hot, is near the top of the building, is well lit with natural light, or faces East or South- has yang properties.
People these days often spend much their time at work you must also consider your working environment. If you work as a coal miner, mainly exposed to underground, yin conditions, then drink tea with warm properties. If you work a job outside in the sun all day, yang conditions, then drink tea with cool properties. If your office is always too cold with air conditioning cranked, then drink tea with warm properties. If you office is too hot and you wish you had air conditioning, then drink tea with cool thermal properties.
By always keeping in mind how the changing environment around you influences your energy, you can always use tea to balance yourself out. This is how you harmonize the thermal nature of tea with the environment. This is how you create greater harmony in your life with a cup of tea in hand.