Heat Stress + Jobsite Hydration Reference

Why this matters

Heat-related illness sends thousands of construction + service workers to ERs every summer. Worse, dozens die. Roof work, attic work, mechanical rooms, outdoor digging - service trades have constant heat exposure. The tech who recognizes heat stress early stays safe + keeps the crew working. This is the field card.

Heat illness spectrum (mild to severe)

Heat rash:

• Red, prickly skin
• Sweat ducts blocked
• Minor; cool + dry

Heat cramps:

• Painful muscle cramps
• Often legs / abdomen
• Caused by electrolyte loss

Heat exhaustion:

• Heavy sweating
• Weakness, dizziness
• Headache
• Nausea
• Cool, moist skin
• Body temp slightly elevated (100-102°F)
• Mental clarity intact (mostly)

Heat stroke (MEDICAL EMERGENCY):

• Body temp over 104°F
• Hot, dry skin (sweating stops)
• Confusion, irrational behavior
• Slurred speech
• Loss of consciousness possible
• LIFE-THREATENING - call 911

Recognizing symptoms in yourself

You may not realize you're in heat stress. Watch for:

• Excessive thirst (you're already behind on water)
• Feeling unusually tired
• Headache developing
• Slight dizziness when standing
• Reduced concentration
• "Off" feeling
• Decreased urine output (OR dark urine)

When you notice any: STOP. Rest, cool, hydrate. Don't push through.

Recognizing symptoms in crew

Looking at others:

• Pale OR flushed face
• Acting "drunk" (impaired judgment, stumbling)
• Confused
• Quiet (extroverted person becomes silent)
• Lying down
• Stopped sweating in hot environment

If you see these in coworker: act immediately.

First-aid response

Mild (heat rash, cramps, early exhaustion):

• Move to cool / shaded area
• Remove excess clothing
• Hydrate (water + electrolytes)
• Rest
• Apply cool wet cloth to head, neck, armpits

Heat exhaustion:

• Same as above
• Add: spray with cool water; fan
• Monitor; if not improving in 30 min, call 911
• If symptoms worsen OR mental status changes: call 911

Heat stroke (suspected):

• 911 IMMEDIATELY
• Move to cool area
• Aggressive cooling: ice packs to neck / armpits / groin; cool water spray + fan; cool wet sheets
• Don't give fluids (unconscious / impaired swallow)
• Monitor airway + breathing

Heat stroke = death within minutes if untreated. Don't wait + see.

Hydration

Daily intake (no exertion): 64 oz water (~half-gallon)

Working in heat: 4 oz water every 15 minutes (16 oz per hour)

Hot day + heavy exertion: up to 32 oz per hour possible

Electrolytes (sodium, potassium):

• Lost through sweat
• Sports drinks (Gatorade, Powerade)
• Electrolyte tablets / powder (Liquid IV, Nuun)
• Salt + small food intake

Don't drink (during heat exertion):

• Alcohol (dehydrates further)
• Sugary sodas alone (osmotic dehydration)
• Caffeinated beverages excessively (mild diuretic; some is OK)
• Energy drinks (high caffeine + sugar)

Urine color check

Best self-test:

• Light yellow / clear = well hydrated
• Dark yellow / amber = dehydrated; drink more
• Brown = severely dehydrated; rest + rehydrate

Customer's bathroom = quick check during a hot job.

Pre-hydration

Start the day hydrated:

• 16-20 oz water with breakfast
• Continue through morning
• Don't wait until you're thirsty (already behind)

Acclimatization

The body adapts to heat over days / weeks:

• Day 1 in extreme heat = highest risk
• Day 5-7 = significant adaptation
• After 2 weeks = mostly acclimated

OSHA recommends:

• New / returning workers: 20% exposure day 1, increasing by 20% per day
• After absence (week+): repeat acclimatization
• Schedule new workers' first weeks accordingly

Heat hazard control

Engineering:

• Shade structures
• Misting fans
• Cooled rest area
• Equipment cooled if possible
• Modify equipment positioning to allow shaded work

Administrative:

• Schedule heavy work for cooler hours (early AM, late PM)
• Rotate hot/cool tasks
• Mandatory rest breaks
• Buddy system (watch each other)
• Production goal reductions during heat waves

PPE:

• Light-colored clothing (reflects heat)
• Breathable fabrics
• Cooling vests (some use ice packs OR phase-change material)
• Cooling neck wraps
• Wide-brim hat OR baseball cap (sun protection)

Specific hot work scenarios

Attic work:

• Attic temp 130-160°F+ in summer sun
• 20-30 min max before mandatory cool break
• Bring multiple water bottles
• Ice pack in cooler
• Schedule for early AM

Roofing:

• Direct sun + heat radiation from shingles
• Surface temp 150°F+ on dark roof
• White / light shingle work much easier
• Hydration + sunscreen
• Plan around weather forecast

Lawn care:

• Direct sun all day
• Equipment hot (mufflers near body)
• Pesticide PPE (rubber boots, gloves) traps heat further
• Schedule difficult work for cooler hours

Pool service:

• Direct sun
• Reflected sun from water + concrete
• Chemicals + heat = additional fatigue
• Hydration + sunscreen

HVAC outdoor / rooftop:

• Equipment hot
• Direct sun
• Refrigerant work + heat = compound effort

Mechanical / boiler rooms:

• Hot indoors
• Limited ventilation
• High humidity
• Take breaks outside

Sun protection (different but related)

Beyond heat:

• UV exposure (skin cancer risk)
• Sunburn (compounds heat stress)
• Eye damage (sunglasses with UV protection)

Use:

• Broad-spectrum sunscreen SPF 30+ (reapply every 2 hours)
• Long sleeves (light, breathable)
• Wide-brim hat OR neck cape
• Sunglasses

Workers outside daily for years have measurable skin cancer rate elevation. Sun protection is occupational safety.

OSHA standards

General Duty Clause: employer must provide safe workplace; covers heat illness even though no specific federal standard.

OSHA heat illness prevention guidance:

• Provide water
• Provide rest
• Provide shade
• Train workers + supervisors

California Title 8 Section 3395: specific state heat illness standard for outdoor work (water, shade, rest, training, emergency response).

Washington, Oregon, Minnesota, Maryland: state-specific heat standards.

Other states: General Duty Clause applies.

Required gear

For hot-weather work:

• Cooler with ice
• Multiple water bottles (sealed; ice cubes too)
• Electrolyte drink mix OR sports drinks
• Cooling towel (microfiber that holds water)
• First aid kit with heat-specific items
• Phone (charged; emergency)

Worker training

Annual heat-safety training:

• Symptoms recognition
• First aid response
• Hydration importance
• Acclimatization

Train BEFORE the hot season; refresh in early summer.

Customer expectations

Customer may not realize:

• Why job is paused / postponed in extreme heat
• Why tech needs frequent breaks
• Why some work scheduled early AM

Educate briefly + customer respects safety. Most customers don't want a tech with heat stroke on their property.

Underlying medical conditions

References

• OSHA Heat Illness Prevention guidance
• CDC NIOSH guidance on heat stress
• Cal/OSHA Title 8 Section 3395
• ACGIH TLVs for heat stress
• Manuall internal: Jobsite Safety Walkthrough, PPE Selection by Task