My husband and I will be spending 8 days in Siena and Florence at the end of October. We would appreciate suggestions as to vitals to pack. We intend to travel the Tuscany area on day trips from the 2 cities.

Warm pajamas. I was in Tuscany in October a few years ago and it got pretty chilly, especially after the sun went down and, unless it's changed, the hotels don't turn on the heat until November.

I don't think there is anything essential to those two cities, I'd bring the same clothes that I would wear in Paris or London -- raincoat, scarf, sweater, neutral color clothing. Comfortable walking shoes are definitely essential. Siena is easier for walking than Florence's cobblestone streets.

Don't worry too much -- you can shop there if you've forgotten something.

Generally heating in condos and hotels is from October 15 to April 15. That is the general rule of thumb in the center and north of the country. A higher starred hotel should certainly be providing heating from October 15 onwards and there may be dispensation from the regional government if there is a cold snap prior to that date.
If the weather is good day temps could be quite warm even reaching the low seventies but will get chilly towards sun down.
Siena is much smaller than Florence so you will have to walk less. Florence does not have cobblestone streets but many of the pedestian streets have large stone blocks which is a different thing - in via Calimala (continuance of Por Santa Maria coming from Ponte Vecchio) is famous for the chalk drawings on its stone which would be pretty hard to do if it was in cobblestone! Walking in Firenze is a bit like walking in Venice. There is no give underneath (unlike macadam) so you do feel it at the end of the day!
For roughly 20 years I have lived just outside Florence for roughly 3 to 4 months a year so do not hesitate to ask for any tip you might want either here or at [email protected]

Extra prescription medicine. I got hit with the April volcano eruption, and I realized was that if I cannot get home as scheduled, I would run out of the medicine.

April volcano eruption - hopefully not in October! Most chemists in the very center of Firenze have at least someone who speaks English. Do not worry.

Probably not in the "vital" category, but we always take a pair of binoculars to better see church ceilings and distant scenery.