Different NHS Trusts have different rules but I would be accessing your Trust terms and conditions and checking on them. Has your boss said this to you by email?
Across Trust policies, the following are usually acceptable when you’re not patient‑facing:
- Short‑sleeved tops (including sleeveless in many Trusts)
- Smart, knee‑length shorts or smart cropped trousers
- Lightweight summer dresses (not low‑cut, sheer, or strappy)
- Sandals (closed‑toe preferred, but many Trusts relax this for office‑based staff)
- No tights requirement in hot weather
- Removing jackets/cardigans even if normally part of “business casual”
Most Trusts explicitly say that comfort and wellbeing in extreme heat is a valid reason to relax the usual dress code.
What is still usually not allowed, even in a heatwave. These tend to be consistent across Trusts:
- Short shorts, denim shorts, or anything “beachwear”
- Strappy tops, spaghetti straps, bandeau tops
- Crop tops
- Flip‑flops (health & safety)
- Anything sheer or low‑cut
- Slogans that could be offensive or political
Even for non‑public‑facing staff, Trusts usually require a “professional appearance”.
Examples from real Trust policies
(These are typical excerpts, wording varies, but the principles are stable.)
Leeds Teaching Hospitals
- Non‑clinical staff may dress “smart casual”.
- Sleeveless tops allowed if “not revealing”.
- Shorts allowed if “tailored and knee‑length”.
Manchester University NHS Foundation Trust
- “Dress should be appropriate to the working environment.”
- Shorts permitted for non‑patient‑facing staff if “smart and modest”.
Barts Health
- “Relaxed summer dress is acceptable for office‑based staff.”
- No denim shorts, flip‑flops, or strappy tops.
NHS England (corporate offices)
- “Smart casual” year‑round.
- No specific heatwave rules, but managers can “exercise discretion”.
Level 3 or 4 Heatwave alert (see below for more on this or see Gov.UK)
Many Trusts issue temporary guidance such as:
- “Staff may dress more informally for comfort.”
- “Short‑sleeved and sleeveless tops are acceptable.”
- “Sandals permitted for non‑clinical staff.”
This is usually emailed out by HR or Estates. The real rule of thumb for non‑uniformed, non‑public‑facing NHS staff, the heatwave dress code is basically: Smart, modest, cool, and safe. If you wouldn’t wear it to a professional office, don’t wear it - but you don’t need to suffer in 30°C either.
Current heat‑health alert level (as of 26 May 2026)
According to the UK Health Security Agency (UKHSA), Amber heat‑health alerts are currently in place for:
- South West
- South East
- London
- East of England
- West Midlands
- East Midlands
Meanwhile, other regions i.e Yorkshire & Humber is under a Yellow alert, which is one step below Amber but still signals possible health impacts. You can check the level on the Gov.UK website for your Trust.
If you are NHS are you in the Union, if so I would be checking your Trust dress code in heatwaves, the Gov.UK website to see what the heat alert is for your Trust and then speaking with the Union.