Weather, water and the outdoor environment

Exterior shoots trade the control of a stage for the beauty and authenticity of real places. With them come the hazards of the natural world: wind that turns frames into sails and topples lifts, lightning that strikes the tallest object in a field, which may be a condor or a crane, heat that brings exhaustion and stroke, cold that brings frostbite and hypothermia, sun, noise from generators and effects, smoke from wildfires, and water in rivers, lakes, oceans and tanks. This lesson covers how to plan for and respond to these conditions, with worked examples on wind loads, lightning distance, heat stress and noise dose, and the Canadian and US guidance that applies.

Planning for weather

Weather planning starts in pre-production and continues hour by hour on the shoot day.

• Check forecasts from national weather services (Environment and Climate Change Canada or the US National Weather Service) for temperature, wind, gusts, precipitation, thunderstorms, heat and air quality.
• Set go/no-go criteria in advance for wind, lightning, heat and cold, so decisions are not made under pressure on the day.
• Assign someone to monitor weather during the day, using apps, radar and on-site instruments such as anemometers.
• Prepare cover sets, shelters, warming or cooling stations and evacuation routes.
• Include weather hazards in the call sheet and the safety meeting.

US Safety Bulletin 38 covers inclement or severe weather and 38A lightning safety. In Ontario, Guideline 33 covers working in extreme temperature conditions.

Wind

Wind is the most common weather hazard for grip and electric crews. It acts on frames, flags, large LED panels, balloons, tents, set walls, lifts and cranes.

• Wind force rises with the square of wind speed (Lesson 6), and gusts can be much stronger than the average speed.
• Large frames, lighting balloons and panels should have defined wind limits, at which they are lowered, struck or secured.
• Lifts and cranes have manufacturer wind limits; the sail area of attached equipment must be considered.
• Anemometers measure wind on site; check at the height of the equipment, since wind is usually stronger higher up.
• Have enough crew, sandbags and ground anchors, and a plan to strike quickly.

Lightning

Lightning can strike miles from a storm and often hits tall objects, such as lifts, cranes, lighting towers, trees and people in open areas. Metal rigging and wet ground increase the danger.

• If you can hear thunder, you are within striking distance. The modern rule is "when thunder roars, go indoors".
• The flash-to-bang method estimates distance: count the seconds between the flash and the thunder.
• Lower lifts and cranes and evacuate elevated positions as storms approach; do not wait for rain.
• Shelter in enclosed buildings or hard-topped vehicles with windows closed, not in tents, open-sided shelters, under trees or near tall equipment.
• Wait at least 30 minutes after the last thunder before resuming outdoor work.
• Assign a person to monitor lightning detection services and call the stop.

Here \( t \) is the time in seconds between the flash and the thunder. Sound travels about 343 m/s, roughly 1 km every 3 seconds or 1 mile every 5 seconds.

Heat

Heat illness is a serious and growing hazard as summers become hotter. Crews may work long hours in full sun, under hot lights, in costumes or protective gear.

• Heat exhaustion causes heavy sweating, weakness, dizziness, nausea and headache. Move the person to shade, cool them and give water.
• Heat stroke is a medical emergency: high body temperature, confusion, collapse and sometimes no sweating. Call emergency services and cool the person immediately.
• Prevention includes water, shade, rest breaks, acclimatization for new workers, light clothing and scheduling heavy work in cooler hours.
• The wet bulb globe temperature (WBGT) index combines temperature, humidity, sun and wind to judge heat stress more accurately than air temperature alone.

Here \( T_{nwb} \) is the natural wet bulb temperature, \( T_g \) the black globe temperature (which captures sun) and \( T_{db} \) the dry bulb air temperature.

In the United States, OSHA relies on the General Duty Clause and a National Emphasis Program for heat, with a federal heat injury and illness prevention standard proposed in 2024; check its current status. Several states, including California, Washington, Oregon, Colorado and Maryland, have their own heat illness rules. California's outdoor heat illness standard requires water, shade at 80 °F, high-heat procedures at 95 °F and training. US Safety Bulletin 35 covers outdoor heat illness prevention.

Cold

Winter shoots in Canada and the northern US bring cold stress.

• Hypothermia begins with shivering, numbness and clumsiness and progresses to confusion and collapse. Warm the person gradually and get medical help.
• Frostbite freezes skin, most often fingers, toes, ears and nose. Wind chill makes it happen faster.
• Dress in layers with windproof outer layers, insulated boots and gloves, and keep spare dry clothing.
• Provide warming stations, hot drinks and scheduled warm-up breaks.
• Ice and snow cause slips and falls; clear paths and use traction aids.
• Cold affects batteries and equipment: lithium-ion batteries lose capacity, cables stiffen and crack, and lift hydraulics can slow.

US Safety Bulletin 34 covers extreme cold and includes a wind chill chart. Canadian provinces refer to ACGIH TLVs and guidance on work-warm-up schedules for cold.

Noise

Generators, special effects, wind machines, playback and gunfire effects can damage hearing.

• Noise-induced hearing loss is permanent and builds with exposure over time.
• Exposure limits are based on an 8-hour average, with an exchange rate that sets how much the allowed time halves for each increase in level.
• Use hearing protection near loud equipment, place generators away from crew, and limit time near loud sources.

Federal OSHA sets a permissible exposure limit of 90 dBA over 8 hours with a 5 dB exchange rate, and requires a hearing conservation program at an 85 dBA action level. NIOSH recommends a stricter 85 dBA limit with a 3 dB exchange rate.

Here \( C_i \) is the time spent at level \( L_i \), \( T_i \) the allowed time at that level, \( L_c \) the criterion level (85 or 90 dBA) and \( q \) the exchange rate (3 or 5 dB). A dose \( D \) above 1 (100 %) exceeds the limit.

Sun, smoke and air quality

• Sun exposure causes sunburn and long-term skin cancer risk; provide shade, sunscreen, hats and long sleeves.
• Wildfire smoke contains fine particles that harm lungs. Check air quality forecasts (the Air Quality Health Index in Canada, the Air Quality Index in the US), reduce heavy outdoor work, and provide respirators where appropriate. Contract Services publishes a fact sheet on protection from wildfire smoke, and California regulates wildfire smoke exposure.
• Dust, pollen and poisonous plants (US Bulletin 27) affect crews on rural locations.

Working near water

Water adds drowning, hypothermia, slips and electrical hazards (Lesson 4).

• Assess water depth, currents, temperature and access before shooting.
• Provide personal flotation devices for crew working near or on water, and lifeguards or water safety personnel.
• Use marine coordinators for boats and water work, and divers only with certified dive teams (US Bulletin 7).
• Cold water causes cold shock and rapid loss of strength, even in summer in northern lakes and oceans.
• Keep line-voltage electrical equipment well away from water, with GFCI protection.

In Ontario, Guidelines 30, 31 and 32 cover underwater operations, water hazards and water locations. In the United States, Bulletins 7, 15 and 17 cover diving, boating and water hazards.