Washing Machines Should Run Cold Except for These Four Specific Items

Should You Wash Clothes in Cold or Hot Water? Here’s the Real Answer
Most people treat laundry temperature like a habit: pick a setting, press start, hope for the best. But the truth is simpler (and cheaper):
Cold should be your default. Heat should be a tool.
Why? Because water heating consumes about 90% of the energy it takes to operate a clothes washer, according to ENERGY STAR.
So every time you choose hot, you’re paying for a mini water-heating session—often without getting better results.
At the same time, there are situations where extra heat genuinely helps (hygiene, allergens, and certain stubborn odours). This guide shows you exactly when cold works—and the four exceptions where it makes sense to turn the temperature up.
You’ll also get:
- a UK-style temperature guide (20/30/40/60°C)
- a simple decision table (great for saving and sharing)
- science-backed hygiene guidance (with references)
- and clear reasons Londoners choose Hamlet Laundry Ltd when heat, hygiene, or time really matter.
The quick answer
Wash cold (20–30°C) for most everyday loads. Use higher temperatures mainly for:
- Towels
- Bedding & sheets
- Underwear & socks
- Athletic wear (sportswear/gym clothes)
Because these categories either:
- hold moisture and build up microbes/odour, or
- are close-contact hygiene items, or
- trap sweat oils in synthetic fibres.
Why cold washing is usually the best choice
1) Cold saves the most energy (because heating water is the big cost)
ENERGY STAR’s guidance is blunt: water heating is ~90% of washer energy use, so cold washes reduce energy use dramatically.
The U.S. Department of Energy also explains that using cooler water is one of the main ways to reduce laundry energy use; switching from hot to warm can cut a load’s energy use in half.
2) Cold is gentler on clothes (less fading, shrink risk, fibre stress)
Heat + agitation speeds up:
- dye loss (fading)
- elastic breakdown (especially in synthetics)
- shrink risk (common in cotton and blends)
So if you’re washing everyday colours, delicates, and most casual clothing, cold is usually the “fabric-safe” default.
3) Modern detergents are designed to work at low temperatures
A.I.S.E. (the International Association for Soaps, Detergents and Maintenance Products) notes that detergent enzymes help remove stains at low temperatures.
That’s a big reason cold washes work better today than they did 15–20 years ago.
Laundry temperature guide (UK-friendly 20/30/40/60°C)
Use this table as your “rulebook.” It’s designed for quick scanning (and Google snippet eligibility).
| What you’re washing | Best default temp | When to increase heat | Why it matters |
| Everyday colours / casual wear | 20–30°C | Only if heavily soiled | Saves energy; protects colour & fibres |
| Towels | 40°C | 60°C occasionally | Moisture + build-up can drive odour; higher temps improve hygiene control |
| Bedding & sheets | 40°C | 60°C for allergies/illness | Guidance for dust-mite/allergy control often recommends hot washing |
| Underwear & socks | 40°C | 60°C for illness/visible soiling | Infection-control leaflets recommend 60°C for heavily soiled/infection-risk loads |
| Athletic wear (synthetics) | 30–40°C | Avoid “very hot” for elastane | Warm helps odour oils; too hot can damage stretch fibres |
Two important notes (honest + useful):
- Always follow garment care labels.
- Home laundry reduces microbes, but it isn’t medical sterilisation. Public health leaflets stress that washing only partially removes micro-organisms and that thorough drying (and ironing where appropriate) reduces contamination further.
The four exceptions: when to turn up the heat
Exception #1: Towels
Towels are basically “moisture traps.” They absorb:
- water
- body oils
- skin cells
- and whatever was on your hands/face
That combination can lead to the classic problem: towels that smell “off” even after washing.
What temperature is best?
- 40°C for regular cleaning
- 60°C occasionally (if the label allows) when you’re tackling persistent odour, mildew-y smells, or hygiene concerns
What the science says (practical version):
A 2023 study examining washing quality versus environmental impact found:
- 40°C (with typical detergent dosing) performed very well for soil removal
- bacterial reduction tended to be highest at 60°C, or at 40°C with higher detergent concentration Taylor & Francis Online
That supports a smart towel strategy:
- don’t default to hot every time
- but use heat strategically when hygiene is the goal
Towel pro tips that actually work
- Don’t overload the drum (towels need space to rinse well)
- Dry thoroughly (damp towels = odour comeback)
- If towels feel stiff or less absorbent, detergent residue might be the issue—reduce detergent and rinse properly
When Hamlet Laundry makes sense for towels
If you’re a busy London household with weekly towel piles (especially family households or shared flats), a professional service removes the “guesswork” and ensures proper wash + dry finishing. Hamlet Laundry offers free collection and delivery across Greater London, making it easy to keep towel hygiene high without using your weekend.
Exception #2: Bedding & sheets
Bedding collects sweat, skin flakes, oils, and allergens. For people with allergies, it’s not just comfort—it can be symptom control.
Hot-wash guidance for dust mite allergy
- Mayo Clinic advises washing bedding in hot water at least 130°F (54.4°C) as part of dust-mite allergy management.
- NHS hospital materials also commonly recommend washing sheets and blankets weekly at 60°C for house dust mite sensitivity advice.
What research shows about mites/allergens
A peer-reviewed JACI study investigated live mite/allergen removal during machine washing and tested cold/warm conditions with detergent and bleach in real residential machines.
Another study in the allergy literature showed common indoor allergens can be largely removed quickly even at moderate temperatures, which is encouraging for lower-temp washing when you can’t go hot—but hot still plays a role when mite control is the goal.
Best-practice bedding approach
- Routine: 40°C (if you’re not allergy-sensitive and items aren’t heavily soiled)
- Allergy/illness weeks: 60°C where fabric allows (or 54°C+ equivalent hot wash)
Why Hamlet Laundry is a strong bedding choice
Bedding is bulky, slow to dry, and easy to “half-clean” at home (especially in winter flats). Hamlet Laundry’s collection and delivery plus full-service laundry/dry cleaning options make it practical for duvets, blankets, and bedding bundles in London.
Exception #3: Underwear & socks
These are high-contact, high-soil items. They also matter most when someone in the household is ill.
What official infection-prevention advice says
NHS-related patient laundry leaflets commonly recommend washing heavily soiled or infection-risk laundry at 60°C, then thorough drying (and sometimes ironing) to reduce risk.
The Health and Safety Executive (HSE) also notes that disinfection is achieved through a combination of temperature (when >40°C), detergent action, and dilution during wash/rinse steps.
Simple rule
- Normal wear: 40°C is often enough (label permitting)
- Illness / visible soiling / infection-risk: 60°C (or the highest safe temp for the fabric)
If you can’t wash hot
- Use a longer cycle (more mechanical action + time)
- Dry thoroughly (and consider ironing cotton items)
- Don’t pack the drum (rinsing matters)
Exception #4: Athletic wear (sportswear/gym clothes)
Gym wear is the #1 “why does this still smell?” category.
Why it’s different:
- Many athletic items are synthetic (polyester blends)
- Sweat oils + bacteria can cling to synthetic fibres
- Repeated low-temp quick washes can leave “permastink”
What the science and reviews say (in plain terms)
A major review on laundry hygiene and odor control emphasizes that temperature is a key factor in pathogen control, often requiring temperatures in the >40°C to 60°C range for stronger inactivation—while detergents also play a role. That doesn’t mean you should boil your gym leggings—it means:
- warm washes can be useful for odor-control loads
- and detergent choice + cycle time matter
Best temperature for athletic wear
- 30–40°C is often the best compromise
- Avoid very hot washes if the garment contains elastane/spandex (to protect stretch and shape)
Gym-wear pro tips
- Wash ASAP after training (don’t leave damp kit in a bag)
- Turn inside out (sweat side gets cleaned)
- Use the correct dose of detergent (too little = odours; too much = residue that traps odours)
- Air dry promptly
When Hamlet Laundry is the smarter solution
If you’ve tried everything and still get lingering odours, that’s when professional processing is worth it—especially if you don’t want to risk damaging technical fabrics. Hamlet Laundry provides wash/iron and dry cleaning services plus free pickup & delivery in London, which suits gym-goers and busy professionals.
How to make cold washing work better (so you don’t “need” hot)
This section is where most blogs stay vague—so here’s the practical checklist.
Cold wash success checklist (save this)
- Don’t overload (clothes need room to move and rinse)
- Use a detergent that works in cold (many modern formulations do; enzymes help at low temps) aise.eu
- Match detergent dose to your load + water hardness (underdosing causes odour; overdosing causes residue)
- Pre-treat stains (especially collars, underarms, food spots)
- Dry thoroughly (damp fabric is where odour and microbes bounce back)
If cold isn’t cleaning well, do this first (before turning up heat)
- Switch from “quick wash” to a longer cycle
- Reduce load size
- Make sure you’re not using too much softener (softeners can trap residues and reduce towel absorbency)
Cold vs hot: pros and cons (quick comparison table)
| Factor | Cold wash (20–30°C) | Hotter wash (40–60°C) |
| Energy use | Lowest (no/less water heating) | Higher (water heating dominates washer energy) |
| Fabric care | Best for colour + longevity | Higher wear risk; shrink/fade more likely |
| Hygiene boost | Good for routine loads | Stronger reduction for hygiene-risk loads; often recommended at 60°C in guidance |
| Best use case | Everyday clothes | Towels, bedding (allergy/illness), underwear/socks (illness), some odour loads |
FAQs
Should washing machines run on cold water?
For most everyday laundry, yes. ENERGY STAR notes that water heating is about 90% of a washer’s energy use, so cold washing cuts energy significantly. Use hotter settings mainly for hygiene or heavy-soil exceptions.
When should I use a 60°C wash?
Use 60°C (if fabric allows) when laundry is heavily soiled, or infection-risk, or for certain allergy-focused bedding routines. NHS leaflets commonly recommend 60°C for these cases, alongside thorough drying.
Does cold water kill germs?
Cold washing can reduce microbes, but public health guidance notes that washing only partially removes micro-organisms and that thorough drying (and ironing where appropriate) further reduces contamination. For higher-risk loads, higher temperatures may be recommended.
What temperature should I wash bed sheets to help with dust mites?
Hot washing is commonly recommended for dust-mite allergy management. Mayo Clinic advises at least 130°F (54.4°C), and NHS materials often recommend 60°C for bedding in dust mite sensitivity advice.
What temperature should I wash gym clothes?
Often 30–40°C is a good balance: warm enough to help odours, not so hot that it damages stretch fibres. Odour control depends on temperature and detergent/cycle time.
Why Hamlet Laundry Ltd is the best option in London for the “hot-wash essentials”
Cold washing is great—until you hit loads that need extra hygiene control, careful handling, or simply more time than you want to spend.
Hamlet Laundry Ltd is built for exactly those moments:
- Free collection & delivery across Greater London (huge for bedding, towel piles, busy schedules)
- Full-service options including laundry, wash & iron, ironing-only, and dry cleaning
- Ideal for:
- bedding & towels that need hygienic finishing
- underwear/socks during illness weeks or heavy-soil situations
- gym wear that keeps holding odour
- time-poor London professionals and families
If you’re trying to be energy-smart at home, the best system is simple:
- Cold wash most things yourself
- Outsource the exceptions to a reliable service when you want guaranteed results without fabric damage or wasted effort
That’s exactly what Hamlet Laundry is for.
Conclusion: the rule that saves money, protects clothes, and keeps hygiene high
Wash cold by default (20–30°C).
Use heat deliberately for: towels, bedding, underwear/socks, and athletic wear.
Let the Experts Handle the Loads That Actually Need Heat
Cold washing saves energy—but towels, bedding, underwear, and gym wear often need careful temperature control and proper drying to stay truly fresh.
If you’re in London and don’t want to guess, Hamlet Laundry Ltd makes it easy with free pickup and delivery, professional-grade equipment, and fabric-safe hygiene cycles.
👉 Book your laundry collection today and stop worrying about wash temperatures.