snow-shoveling-strategist

Use before or during snow clearing — builds the safest plan for YOUR driveway (area math, snow water-equivalent weight, which tool per depth/condition, where to throw so you don't entomb your car or re-shovel the same snow), paces the effort (cold-air angina risk, %MHR work/rest cycling), and covers the cardiac red flags that mean stop-now plus ice-melt chemistry for the surface left behind.

Snow shoveling sends a measurable spike of people to ERs every storm — cardiac events (cold-air vasoconstriction + static gripping + upper-body load the heart unlike legs), back injuries, and ice falls. Meanwhile the actual shovel work is plannable: how much snow weighs, where it goes, which tool, and in what order — so you move each kilogram once.

When to Use

• Before/during/after a storm: plan the clearing
• Deciding: shovel now vs wait for snow to end; shovel vs snowblower vs ice-melt
• Deep or wet snow: pacing and load limits
• Driveway + car + mailbox + hydrant layout: where to put snow so it doesn't come back
• Anyone 45+ or with cardiac risk factors: pacing protocol
• Post-storm ice: which melter for which surface/temperature

Don't use for: medical emergencies (chest pain = ambulance, below); roof snow (different danger class — falling + collapse).

The Method

1. plan — driveway/steps geometry → area; storm depth + snow type → total weight of snow (water equivalent); tool verdict per condition; WHERE to place snow (stack-and-throw plan that never re-handles snow); order of operations (car last, exit path first).
2. pace — your age/fitness/risk inputs → work/rest cycles, effort class, and the cardiac red-flag list with stop-now criteria.
3. salt — pavement temperature (not air!) + surface type → melter choice with exact application rate, what NOT to use (concrete <1yr, brick, pets), and pre-treat vs post-treat strategy.

Quick Start

bash

# 2-car driveway 6x9 m, 25 cm heavy wet snow, ending 7am
python3 scripts/snow_plan.py plan --area 6x9 --depth 25 --snow wet --ends 07:00 --now 05:30

# 55yo, decent shape, one cardiac risk factor, alone
python3 scripts/snow_plan.py pace --age 55 --fitness moderate --risk-factors 1 --alone

# Ice after clearing: pavement -6C, concrete 3 years old, dog
python3 scripts/snow_plan.py salt --pavement-temp -6 --surface concrete-3yr --pets

Stdlib-only Python 3. Offline.

Snow Weight Physics (the core numbers)

Snow type	Density (kg/m³)	10 cm on 50 m²	Shovel-load (5 L)
Fluffy/powder (≤ −8 °C)	50–100	250–500 kg	0.3–0.5 kg
Average	100–200	500–1000 kg	0.5–1.0 kg
Wet/heavy (0 °C)	300–400	1500–2000 kg	1.5–2.0 kg

A "small" 2-car driveway with 25 cm of wet snow = 5+ tonnes. That's the number that reframes "quick cleanup" — and why tool choice and pacing aren't optional.

Tool Verdict Table

Condition	Tool	Why
< 8 cm powder	Pusher/snow scoop	Push, don't lift
8–15 cm any	24–28" shovel, push-then-throw	Lift less per pass
> 15 cm wet	Snowblower, or shovel in LAYERS (skim 10 cm passes)	Full-depth lifts = back + heart
Any depth + ice crust	Ice scraper/chipper for crust, then pusher	Shovel edges die on ice
End of driveway (plow ridge)	Separate plan: heaviest, do LAST, in layers	Plow ridge = wet + dense

Cardiac Reality (the part nobody plans)

Cold air constricts coronary arteries; static gripping raises blood pressure; arm work above waist is less efficient than leg work — heart rate and BP spike disproportionately. Shoveling can hit > 85% max HR in sedentary adults within 2 minutes.

Stop NOW and call emergency services if: chest pressure/pain (even "just" tightness), pain radiating to jaw/neck/left arm, unusual shortness of breath, light-headedness, cold sweat, nausea, palpitations. Women and diabetics: atypical presentations (sudden fatigue, back pain, "feeling off") count.

Common Pitfalls

1. Waiting for the storm to end on big dumps. 40 cm in one clearing = twice the load per shovel. Clear at 10–15 cm marks (the plan computes pass timing).
2. Lifting with the shovel far from the body. Every cm of lever arm multiplies spinal load. Hands apart on the shaft, load close, pivot with legs/hips, never twist under load.
3. Throwing snow onto the cleared path / car / next section. Snow moves ONCE. The placement plan stacks downwind, back, and away from returns.
4. Coffee + shoveling right out of bed. Caffeine + cold + immediate exertion stacks the BP spike; warm up 5 minutes inside, dress in layers, breathe through a scarf (warms intake air).
5. Salt before clearing bulk snow. Melters drill through a few cm, not 20. Clear first, then treat the surface; pre-treat only thin events/frost.
6. Ignoring the plow ridge. The city will refill your driveway apron AFTER you clear it — timing the apron last saves re-doing it.
7. Wet snow + full shovel = 2 kg × thousands of lifts. Skim layers; the plan prints the per-load target weight for your snow type.

Verification Checklist

• Area + depth + snow type measured (snow type: squeeze test — powder falls apart, wet packs into a ball)
• Total tonnage known before starting
• Tool matches condition table
• Placement decided before the first push (downwind/back/melt path)
• Work/rest cycle set; phone in pocket; someone knows you're out
• Surface treated with the right melter at the right rate AFTER clearing, not before

References

• references/technique-and-safety.md — biomechanics (lift, carry, throw), layer-clearing method, cardiac risk physiology, warm-up, and the full red-flag list
• references/ice-melt-chemistry.md — melter table by pavement temperature, surface compatibility (new concrete, asphalt, brick, pets/plants), rates, and pre/post-treat strategy