On top of the emergency blanket, I also have a couple of these hand warmers.
You should use a pair of these hand warmers if they have them:
During the later parts of the marathon your hands tend to get cold because most the blood goes to the working muscles.
https://www.amazon.ca/HotHands-Hand-Toe-Warmers-Activated/dp/B06ZYW6HDK/ref=asc_df_B06ZYW6HDK/?tag=googlemobshop-20&linkCode=df0&hvadid=341773267873&hvpos=&hvnetw=g&hvrand=2038051260049003849&hvpone=&hvptwo=&hvqmt=&... these can be lifesavers in terms of avoiding frostbite
In all seriousness though if you haven't tried handwarmers and you have a problem with your hands getting too cold, give them a try.
Amazon link - you can get them at many retail stores in the area, usually in the camping section
Ya man avoid heat at all costs, HotHands Hand & Toe Warmers - Long Lasting Safe Natural Odorless Air Activated Warmers - 24 Pair OF Hand Warmers & 8 Pair Of Toe Warmers https://www.amazon.com/dp/B06ZYW6HDK/ref=cm_sw_r_cp_api_i_8FZiCbW2B320Z