Hi,
First time poster and I come with a question.
I live in South Wales, UK and the temperature here is a bit chilly, especially for my two millis. I have an under tank heat mat which heats the soil to a 'warm to the touch' temperature, from a basic dial thermometre it reads about 25c warm.
From a thermometer I have about mid way up the tank wall the air temp stays roughly around 18c, which is a bit on the cold side from what research I've done.
I was wandering if 25c soil temp, but 18c air temp is okay?
Is it the soil temperature or air temperature I want to be concerned with? With a dim heat lamp or side mounted heatmat be useful in this situation? These are my first millipedes and want them to be comfortable, so any advice is welcome 
Many thanks in advance,
Reece