When a base layer comes with a warning not to sleep in it because it’s too warm, you should know what you’re getting; but just to make it crystal-clear, the Xcelcius Megatherm top also comes with a certified -25 deg C rating. Oh yes, it’s a hot one. Looking more like a sweatshirt than a base layer, it has a fleecy lining and is a fairly heavy and solid item of clothing. As such it won’t be suited to all activities and all weathers. On a fast summer trek this is the last thing you’ll want to be wearing – you’ll melt faster than the Wicked Witch of the West. But for slower climbs in extremely cold conditions or winter camps it’ll be perfect, trapping warm air next to the skin and maintining body temperature. As well as offering insulation, Xcelcius’ Viloft fabric (which is made from eucalyptus wood pulp) draws perspiration away from the skin and is bacteria-resistant, so it remains odour-free for longer.
Material 50% viloft (eucalyptus), 50% polyester
Colours blue (men’s); white (women’s)
Sizes S-XXXL (men’s); XS-SL (women’s)
Weight 409g (size men’s L)
Of the base layers we looked at, the Xcelcius Megatherm is the best for extreme cold.
Review by Ben Weeks
First published in Trail magazine Spring 2013