Hypothermia and frostbite are medical emergencies that develop on New York City construction sites every winter. They don't require extreme temperatures — wind, moisture, and fatigue can bring on hypothermia at temperatures above freezing. Every foreman and worker must recognize the signs early, because a worker with moderate hypothermia cannot recognize it in themselves.

• Frostnip (mildest): Red, tingling skin — most common on ears, nose, fingers, toes. Rewarm in warm (not hot) water; do not rub. Worker can continue if fully rewarmed and symptoms resolve
• Superficial frostbite: White or grayish-yellow skin, waxy or firm to touch, blistering within 12–36 hours. Remove from work, rewarm, transport to medical facility
• Deep frostbite: Hard, black skin — tissue is frozen. Call 911. Do NOT rewarm in the field — rewarming before hospital significantly worsens tissue damage

• Mild (90–95°F): Intense shivering, impaired coordination, slurred speech — worker may deny anything is wrong
• Moderate (82–90°F): Shivering STOPS — this is a dangerous sign, not improvement. Confusion, drowsiness, muscle rigidity
• Severe (below 82°F): Unconsciousness, no shivering, very slow pulse. Call 911 immediately. Handle gently — cardiac arrhythmia can be triggered

• Move the worker to a warm, sheltered area immediately
• Remove wet clothing; replace with dry insulating layers or blankets
• Provide warm (not hot) beverages if conscious and able to swallow — no alcohol
• Do NOT rub or massage frostbitten or hypothermic limbs — it causes vascular damage
• Call 911 for any worker with moderate or severe hypothermia or deep frostbite