Masonry Magazine October 2005 Page. 18
COLD WEATHER WORK
Varieties of available admixtures, which can accelerate mortar setting. Keep in mind, the design professional of record must approve the use of such admixtures since some can be damaging to the masonry or to imbedded metal. This is especially true of those containing chlorides.
Finally, instead of straw, contractors can now use insulating blankets, electric blankets or heat lamps to retain the heat of cement hydration for extended periods.