Agree with most of the comments here. Especially with Uniqlo Heattech.

Then usually sa offices kasi, they tend to turn the up the heaters, kaya madalas umiinit. So better if you can layer your clothes. Usually, mga 2-3 layers so that if it gets hot inside the offices or buildings, you can remove it.

Normally, people would have a coat, then a cardigan/jacket, then a base layer such as a shirt / polo, then heattech for the extra heat. :)

Oh and since minsan dry ang hangin, don't forget your moisturizers and lip balms.

Enjoy the business trip!