The unprecedented warm weather in Scotland’s mountains in recent weeks looks set to end – and mountaineering experts are reminding walkers, climbers and skiers that it’s time to replace T-shirts with fleeces and make sure they have their ‘winter heads’ back in place. The unseasonably high temperatures and lack of snow have meant many hill-goers have abandoned crampons, ice-axes and skis in favour of more summery options such as hill walking, climbing and mountain biking. However, although the daffodils are just on the cusp of flowering in the lowlands, the weather is set to change back to more usual conditions…