Seasonal operations
The kitchen that coped all winter falls apart in July because the margin was already gone. Why airflow is a heat control, and why early summer is the smart time to restore it.
Seasonal operations
Nothing about the kitchen changed - same menu, same kit, same brigade. What changed is the margin. All winter, cool make-up air hid the fact that the extract system was moving less air than it should; in a heatwave, with the room starting 15 degrees warmer and the fridges fighting for their lives, that hidden deficit becomes the difference between a hot kitchen and an unworkable one. A grease-loaded system can be down 30-50% on its design airflow - and summer is when the missing half gets noticed.
The legal position
No - and that surprises people in both directions. UK law sets no maximum workplace temperature, precisely because kitchens, bakeries and foundries generate heat as part of the work. But the absence of a number is not the absence of a duty: heat is a hazard like any other, and employers must assess and control it under the same law that covers everything else. HSE's hierarchy is explicit that engineering controls - removing heat at source, ventilation that actually works - come before rest breaks and rotation. In a kitchen, the single biggest engineering control is the canopy overhead, which makes its condition a health and safety matter, not just a hygiene one.
The knock-on rules follow the airflow. A gas cookline's interlock exists to prove the extract is running before gas flows - and a system so loaded it cannot demonstrate meaningful airflow is heading for interlock trouble at exactly the moment the kitchen can least afford downtime. Make-up air matters just as much in summer: extraction can only remove what replacement air lets it, and a kitchen with its windows shut against the heat and its make-up path blocked by a delivery stack is strangling its own biggest cooling system.
The compounding
Heat compounds through everything at once, and the bill arrives on three fronts:
The full bill is bigger than comfort, as we set out in the hidden cost of a hot, poorly ventilated kitchen.
Summer also changes what the kitchen is asked to do. Beer gardens, terraces and event trade push covers up in exactly the months the room is hardest to work in; menus drift toward the grill and the fryer; service runs later into warm evenings. The system is being asked for more airflow, at higher ambient temperatures, with more grease going up it per week - a triple squeeze on capacity that was already reduced if the last clean is a distant memory. The kitchens that feel summer worst are almost never the ones with the hottest postcode; they are the ones that entered it with the least margin.
The intervention
The seasonal logic runs one way. Cleaning the system before peak summer returns the airflow when it is worth most - a cooler room, fridges under less strain, a brigade that lasts the shift. It also lands before the busiest cooking months load the ductwork further: a system cleaned in June carries the summer's grease with headroom, while one left until autumn spends the hottest weeks at its worst. And if the kitchen's hours have crept up with summer trade, the cleaning interval itself may need re-banding - the logic is in how often to clean a kitchen extraction system. The certificate that follows does double duty in the file: hygiene evidence for the EHO, and proof the biggest heat control in the building was actually working.
There is a scheduling dividend too. Early summer sits between the spring rush and the holiday peak for most operators, which means quiet mornings exist to clean in without losing trade - and contractor diaries are kinder in June than in the pre-Christmas scramble when everyone else remembers their certificate at once. A kitchen that fixes its extraction date to the season rather than the renewal letter gets the airflow when it pays most and the disruption when it costs least.
Questions
There is no statutory maximum temperature, so no automatic threshold exists. Workers do have protection under employment law if they reasonably believe conditions pose serious and imminent danger, but that is a high bar aimed at genuine emergencies. The practical route is the employer's duty: heat is a hazard that must be assessed and controlled, and a kitchen that is dangerously hot with no controls in place is a health and safety failure whatever the thermometer says.
If the system is grease-loaded, yes - measurably. Extraction removes the heat, steam and combustion products the cookline produces; a system down 30-50% on design airflow is leaving that share of the heat in the room. Cleaning cannot make a badly designed system exceed its specification, but it restores what the specification promised - and in a kitchen that coped last summer and struggles this one, the loading is usually the difference.
Not directly - TR19 Grease bands follow cooking hours, not the calendar or the weather. What summer changes is usually the hours: longer evenings, garden covers, event trade and grill-heavy menus push many kitchens up a usage band without anyone noticing. The seasonal question worth asking is not 'is it hot' but 'are we cooking more than the interval was quoted on' - and if the answer is yes, the re-banding conversation is due regardless of the forecast.
Phoenix Duct Clean · by the numbers
TR19 Grease extraction cleaning scheduled ahead of peak season - loading assessed, system cleaned, certificate in the file before the first heatwave.