What should a 75 year old man wear to attend a conference in late August? To walk around Shanghai?

I am attending a conference at the University in Shanghai at the end of August. I expect to be in the conference most of the time, but there will also be some free time to explore Shanghai. I understand it can be sweltering hot and humid at that time, what should I pack? Is it appropriate for a man of my age to wear shorts and T-shirt for the free time, and do I have to wear a jacket, shirt and tie to the conference?
Thank you.