Iv recently started power walking to the next village and back(about 4 miles)and i usually go first thing in the morning.I need a jacket as its still cold first thing but i sweat quiet a lot so i need one thats breathable and with mesh panels,i have a summer weight one thats too thin for this time of year.Can anyone recommend one? Iv seen a nice one on the sweaty betty website but its very expensive,it also needs to be light enough to tie round my waist if i get to hot.