Heat and summer health in Vaud
Hot days and heatwaves are becoming more frequent in Switzerland. This page covers heat warnings, how to protect yourself, sun and UV, lake water quality and drinking water.
Key facts
- Heat warnings: MeteoSwiss issues them at danger levels 2, 3 and 4; a heatwave (level 3) means a daily mean temperature of at least 25 °C for at least 3 days.
- Vaud heat plan: the canton runs a heat monitoring period from 15 May to 15 September.
- Drink regularly: at least 1.5 litres a day (FOPH); tap water is the FOPH's first choice.
- Sun: strongest between 11:00 and 15:00; use sunscreen SPF 30+ with UVA protection.
- Unwell? Vaud on-call doctors' phone line (Centrale téléphonique des médecins de garde) 0848 133 133; heatstroke or serious emergency: 144.
1. Heat warnings and the Vaud heat plan
MeteoSwiss danger levels for heat:
| Level | Meaning |
|---|---|
| 2 | Daily mean temperature of at least 25 °C for 1 or 2 days |
| 3 | Daily mean temperature of at least 25 °C for at least 3 consecutive days |
| 4 | Daily mean temperature of at least 27 °C for at least 3 consecutive days |
Warnings are only issued for levels 2, 3 and 4. You get them on the MeteoSwiss app and website and through Alertswiss: see Alertswiss and civil protection, which also links the canton's emergency notices (including heatwaves).
Vaud: since 2009 the canton has a heat plan (dispositif cantonal fortes chaleurs). During the monitoring period (15 May to 15 September) it follows the weather daily; depending on the MeteoSwiss level and health data, the head of the health department can trigger the heat plans of communes and care institutions. Advice, a quiz and fact sheets are on vd.ch/chaleur.
2. Protecting yourself in the heat
FOPH advice, in short:
- Stay in the shade and in cool places. Avoid hard physical activity in the hottest hours (11:00 to 15:00 midday sun, 15:00 to 17:00 high temperatures); move sport to early morning or late evening.
- Drink regularly, at least 1.5 litres a day, and avoid alcohol and sugary drinks. Ideally drink tap water.
- Wear light clothes; take cool showers; cold towels on the neck and forehead help.
- At home: close windows and shutters during the day, air the rooms at night and early morning.
- Keep an eye on people at risk around you (older people, people with chronic illness, pregnant women, small children).
The canton's heatwave notice adds: if your health gets worse, call your doctor or the medical on-call line 0848 133 133; for serious discomfort (confusion, loss of consciousness) call 144. More on emergencies: Health and emergencies.
Dry weather and fire bans: for barbecues and outdoor fires see Forest fires, barbecues and outdoor fires in Vaud; for fireworks see Fireworks rules in Vaud.
3. Sun and UV protection
FOPH advice:
- The sun is strongest between 11:00 and 15:00: stay in the shade or indoors if you can.
- Wear covering clothes and a hat, and sunglasses marked CE with "100 % UV" or "UV 400".
- Apply plenty of sunscreen with UVA protection and SPF 30+; reapply after a while and after swimming.
- Take extra care when it is cloudy, at altitude, and near snow, water or sand (reflection).
4. Lake water quality in Vaud
- Vaud has about a hundred public beaches, including 67 on Lake Geneva.
- Communes have water samples taken at least twice per bathing season; the cantonal Consumer Office (OFCO) analyses them. Bad results lead to quick re-sampling; if swimmers' health may be at risk, OFCO requires signs on site advising against or banning swimming, and informs the cantonal doctor.
- Results for a beach during the season: the commune responsible must give them to users who ask.
- Cyanobacteria (blue-green algae) are handled by the cantonal environment office (DGE).
Where to swim, pools and lake safety rules: Swimming pools and the lake in Vaud.
5. Tap water and public fountains
- The FOPH recommends tap water for staying hydrated in the heat.
- Lausanne: the City says most of its roughly 300 fountains are supplied by the Water Service and give drinking water; fountains are being fitted with an "eau potable" sign. Drink from fountains marked as drinking water.
- Other communes: Prilly and Ecublens get their tap water from the Lausanne Water Service (Prilly, Eau potable, Ecublens, Services industriels). Across Vaud, public fountains fed by private springs must carry an "Eau non potable" sign, unless the spring is protected and regularly tested; fountains on the public network are drinking water (État de Vaud, Aide-mémoire eau potable). If a fountain says "non potable", do not drink.