My 4 month old is using a halo sleepsack, however, I have a couple other sleepsacks (Carters) which have arms. I see Halo advertises their's safer because there are no arms. Are arms really a SIDS risk? and if so as winter draws near how are others dressing their babies for sleep. Seems to me their arms will get chilly. I currently dress her in a onesie, pj's and socks and the halo.