Metal detector batteries are definitely at the mercy of temperature. Low temperatures will drain the power from batteries quite rapidly. One may wish to remove the battery pack from the cuff assembly if so equipped and put the pack on your belt beneath your jacket or raincoat. This keeps batteries warmer and dry. In cold weather an extra set of GOOD batteries is a must and they should be kept warm. Hot weather is also a drain on batteries. Searching in hot weather with high ambient temperatures will definitely have an effect on your searching. Many feel that searching in hot weather is not as damaging to the detector or as dangerous to the operator. There is good thought behind this . Man can generally tolerate heat better than cold and if one gets too warm, shade can be sought for a brief rest. Exactly the same can be said for the detectors batteries. A little respite from the direct blazing sun and some occasional shade will do wonders. Be aware and be prepared for a success.