Bug-Out Bag for Phoenix

How heavy should it be?

A common backpacking rule of thumb is to keep a loaded pack at or under about 20% of your body weight (about 30 lb for a 150 lb adult), per REI. Water weighs 8.34 lb per gallon, so 2 gallons is already about 17 lb. That's why you shouldn't plan to walk long distances in summer heat.

• Kids, older adults, and anyone with health conditions should carry much less. Put the heavy water in a wagon, cart, stroller, or car (see wheels and other ways to move).
• Pack heavy items (water) close to your back and centered.
• Do a test walk with your full bag on a cool morning before you ever need it.
• Wear broken-in shoes and pack wool/synthetic socks plus a light sheet or long-sleeve layer for sun: see our desert cover-up & footwear article.

Car bag vs. home bag

In an ASU/UC San Diego study in Tempe, cars parked in the sun reached an average 116°F inside after one hour, with dashboards at 157°F (ASU News). That heat damages kit contents:

• Medications: CDC warns insulin, inhalers, and epinephrine auto-injectors can degrade or malfunction in hot cars (CDC). Keep meds in your home bag, and grab them when you leave.
• Water bottles: an ASU study found PET plastic bottles release more antimony as temperature rises, potentially exceeding the EPA limit after about 38 hours at 65°C (149°F) (Westerhoff et al., ASU). Rotate car water often, keep it shaded, or use stainless steel bottles.
• Batteries & power banks: heat speeds permanent lithium-ion capacity loss (Battery University). Don't store power banks in a summer car.

Our suggestion: keep the full bag (with meds and electronics) at home near the door. Keep a smaller heat-tolerant car kit with water you rotate, a sunshade, a hat, Mylar blankets, a first aid kit, and walking shoes.