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Unhoused survival and extreme weather triage: hypothermia and heatwaves

Living unsheltered on the streets, in tent encampments, or in makeshift wilderness camps exposes individuals to severe environmental hazards. Without climate-controlled housing, extreme summer heatwaves cause fatal heat stroke and winter freezes cause severe hypothermia, frostbite, and limb amputations.

Knowing how to construct thermal insulation buffers from everyday materials, access emergency cooling centers and warming shelters, and identify early medical decompensation saves lives.

Winter extreme cold survival (Preventing fatal hypothermia)

The ground is a massive thermal heat sink. Direct contact with frozen concrete or wet soil siphons body heat through conduction up to 25 times faster than cold air.

  1. Build a raised ground barrier:
    • Never sleep directly on bare concrete, soil, or asphalt.
    • Stack wooden shipping pallets, thick layers of corrugated cardboard (at least 4 to 6 layers thick), or dry straw underneath your tent or sleeping bag. Cardboard traps dead air, creating vital thermal insulation.
  2. Keep sleeping gear completely dry:
    • Wet clothing or damp sleeping bags destroy insulation value and lead to fatal hypothermia within hours. Keep a clean, dry pair of wool or synthetic socks sealed in a plastic grocery bag strictly reserved for sleeping.
    • Change out of sweaty daytime clothes before getting into your sleeping bag.
  3. The space blanket vapor barrier technique:
    • Wrap an inexpensive mylar reflective emergency blanket between two layers of conventional wool or cotton blankets.
    • Placing mylar directly against bare skin causes sweat condensation, making you colder. Sandwiching mylar inside blankets reflects up to 90 percent of radiant body heat back to your core while absorbing moisture.
  4. Insulate feet and extremities:
    • Frostbite strikes toes, fingers, nose, and ears first. Wrap feet in dry socks, slip plastic grocery bags over the socks as windbreaks, and place feet inside shoes or extra sleeping bags.
    • If toes become pale, waxy, or numb, do not rub them vigorously with snow (which shears frozen capillaries); warm them gradually against your abdomen or armpits.

Summer extreme heat survival (Preventing heat stroke)

Urban concrete canyons and asphalt radiate intense stored thermal heat, creating lethal heat domes:

  • Hydration with electrolytes: Drinking plain water without salt or minerals during heavy sweating causes dangerous hyponatremia (water intoxication). Seek water infused with electrolytes, pinch salt into water, or consume broth.
  • Locate public cooling zones: Spend the hottest hours of the day (11:00 AM to 5:00 PM) inside air-conditioned public spaces: public municipal libraries, transit centers, shopping malls, cooling center shelters, and splash parks.
  • The evaporative cooling bandana: Soak a cotton t-shirt, bandana, or towel in cool water and drape it around your neck and across your carotid arteries. Re-wetting the fabric continuously lowers blood temperature circulating to the brain.
  • Avoid enclosed, direct-sun tents: Temperatures inside a nylon tent pitched in direct summer sunlight can exceed 130°F (55°C) within minutes, causing fatal heat stroke. Relocate sleeping areas to shaded bridge underpasses, park tree canopies, or building shadows.

Finding emergency shelters and community resources

  • Dial 211 (United States and Canada): Call 211 from any mobile phone or payphone to connect with local health and human service dispatchers. Ask for the locations of active emergency warming centers, cooling stations, severe weather hypothermia beds, and mobile soup kitchens.
  • Hospital emergency departments: Under federal emergency medical treatment regulations (such as EMTALA in the United States), hospital emergency rooms cannot turn away individuals experiencing acute medical distress, severe hypothermia, heat exhaustion, or infection, regardless of insurance status or ability to pay.