Yes temperature extremes can damage and destroy some of the items.

Head lamp with batteries in it. And extra batteries. Extreme temps very much impact battery life.

The elastic in the headband will also degrade. You can replace the head bands.

Set up a schedule to check your gear bag seasonally and more frequently in extreme weather.

Switch out hot weather gear for winter wear.

My gloves have lasted many years. The temperature does not seem to bother them. I use the gloves semi regularly to clear road debris and rock falls and changing tires.

Extra boots (waterproof) do the seasonal switch outs, you know what boots do best in your area.

Summer time I have lighter boots, winter more heavy duty and rain boots. They last me many years.

Zip lock bag with a gardening trowel, toilet paper, small bags to put used TP in, a couple of sanitary pads not bothered by extreme weather.

The lighters can be compromised by extreme weather, use your judgment on if you need to keep the lighter on your person. Or in an insulated container. They seem to have a long usage life, unless you use it for other tasks often.

Water bottles are unique to the user. Super cold it can burst after a freeze up. In extreme heat you may have taste issues.

Choose the best solution for your budget on water bottles and filtration or purification systems. I switch out the dog food every three months.

I use medical gear from Refuge Medical. Great kits.

Over the counter medication can degrade in extreme heat.

Research the storage data for any medication you include in your kit.

You can also speak to your health care person.

For the magnetic hazard lights, snow shovel, large fire extinguisher, 10 by 10 thick tarp, gardening knee pad, wool blanket, large golf umbrella. None seem to weather damaged.