Controlling legionella comes down to one principle: keep water out of the 20-45C range where it breeds, and never let it sit still. The HSE temperature regime, the scalding balance and thermostatic mixing valves, and the monitoring routine that proves it works.

Almost every organisation that controls a building needs a legionella risk assessment, and most that think they are exempt are not. Who legally needs one, what it must cover, who can carry it out, and how often it must be reviewed.

Legionella lives harmlessly in most water systems and only becomes dangerous when a system lets it multiply and produces a breathable spray. What legionella is, how it causes Legionnaires’ disease, where the risk sits, and what UK law requires.

Regulation 10 fire door checks, what FD30 and FD30S mean, how to check a fire door, and the failures that come up most often.

The five UK fire extinguisher types, their colour codes, the fire classes each is rated for, and which must never be used on electrical equipment.

The five steps of a fire risk assessment, who the responsible person is, and why a written record is now compulsory in England and Wales.

Abrasive wheels no longer have their own regulations — PUWER 1998 governs them, and only a trained competent person may mount a wheel. The hazards that actually cause injuries, what training must cover, and the seven checks that get skipped.

There is no legal requirement to have mental health first aiders — HSE considered adding mental health to the First-Aid Regulations and decided against it. What the law does require, what HSE actually recommends, what the MHFA England trademark means, and what the role really involves.

CPR does not restart a stopped heart — it buys time until a defibrillator arrives. What cardiac arrest is, why agonal gasping is missed, the compression depth and rate per Resuscitation Council UK, hands-only versus 30:2, and why an explainer is not training.