am planning to visit Wuhan in January, what precautions must I take since I will be coming?

May, I don't know when you will arrive there. However, you are likely to encounter Spring Festival Travel Rush if you come between Jan. 23 and Feb. 18. So you'd better book your arrival and departure train tickets in advance. Also you should be very careful when you take bus or train in case you lose something. You'd better bring masks because the air quality in Wuhan isn't good in recent days.

I checked the weather forecast. It won't be very cold at the beginning of January, 2016. However, I still suggest you bring some warm winter clothes in case the weather changes greatly.

Thank you Peter

...I meant to ask- what precautions must I take not to become ill while am there?

Just wear warm clothes and masks. And you'd better not try many street snacks if you have indigestion problems. These food are not very hygienic.