I just ran across this:
It seems that someone on the forum was talking about this ...
The instructions say to place the contraption in a small room that is kept at 80° to 90°F.
" If needed, a small space heater can help reach that temperature, and lower the humidity at the same time."
I can't tell from the picture if that's a thermometer or a clock. If a clock is included in the kit, I wonder if it could be exchanged for a calendar for a modest fee.