Looking for a base layer that I will wear under body armour and a smock 24h a day. Used on exercise that involves the usual section attacks casualty extraction. Does anyone have any experience with merino base layers they would recommend? There are reviews on here with icebreaker 200 layers and people say their great and would not go back to HH but it's the kind of kit sold by snow and rock (winter sports) are they too heavy for this kind of use? Seen Haglofs Roundneck however no one has my size (small). SmartWool do a midweight option, would this be more sutible maybe.