I tend to run cold and have done previous dynamos when it's been very hot in the day and still warm at night. Arm warmers and a wind proof got me though the 2 - 3.30am cold/tired slot quite well.
This. Arm warmers and knee warmers plus a lightweight windproof take up next to no room and could make the difference between comfortable and miserable.
I'd add a buff to the list as well as it seems to prevent getting a stiff neck if you get cold.
I tend to run cold and have done previous dynamos when it's been very hot in the day and still warm at night. Arm warmers and a wind proof got me though the 2 - 3.30am cold/tired slot quite well.