The environment in the Southern Alps is subject to extreme weather changes and shouldn't be underestimated. Essential clothing and equipment you need to have on the mountain are:
For you and your family
Minimum of 3 layers of warm clothing (thermal, shirt, woolen jersey or polar fleece)
Waterproof and wind proof jacket and trousers
Hat and warm, waterproof gloves or mittens
Spare dry clothing, especially warm socks
Sunscreen and sunglasses
For your car
Chains that fit your car's tyres
If you are planning to go backcountry you must carry an avalanche transponder and let Mt Dobson management know when you are leaving, where you plan to go and when you expect to return. Let them know when you get back to the base area.
Outside of the patrolled ski area, avalanche danger is a very real threat. The risk of an avalanche can change from day to day depending on snow and weather conditions. Check the threat level before you leave and be prepared.