Recovery travel guide
Hair transplant recovery, day by day
Grafts are fragile for the first 7 to 10 days. The rules are about keeping the scalp out of the sun, dry except for the clinic's washing method, cool and untouched.
When the limits lift
Within the 10 days this guide covers, according to the cited guidance:
- Sun on the scalp: still off-limits on day 10. Ask your surgeon when it is safe.
- Swimming, sea and pools: still off-limits on day 10. Ask your surgeon when it is safe.
- Sweating and exercise: with care from day 4.
- Hammam, sauna and steam: still off-limits on day 10. Ask your surgeon when it is safe.
- Hats, helmets and caps: with care from day 5.
- Crowds and head contact: with care from day 7.
- Alcohol: with care from day 4.
- Smoking and nargile: still off-limits on day 10. Ask your surgeon when it is safe.
- Flying home: with care from day 1, OK from day 2.
Confirm with your surgeon. These are general activity limits from published aftercare guidance. Your clinic's written instructions always come first, and they may be stricter or looser for your procedure.
At a glance
- How long to stay
- 3 to 5 days in the city is typical; many patients stay 7 to 10 to see the crusts through
- What the rules are about
- Grafts are fragile for the first 7 to 10 days. The rules are about keeping the scalp out of the sun, dry except for the clinic's washing method, cool and untouched.
Recovery timeline
- Days 1 to 3
Clinic check and first wash. Swelling of the forehead often builds and may reach the eyes. No sun on the scalp, no hat pressing on grafts, no sweating, no bending far forward.
- Days 4 to 7
Swelling settles. Light sightseeing with breaks, in shade, with a loose clean hat only if your clinic allows it. Still no swimming, steam or exercise.
- Days 8 to 10
Crusts loosen and fall away with washing. Longer outings are fine but the scalp stays out of direct sun, water and heat for weeks yet.
- After you fly home
Clinics commonly ask for 2 weeks without exercise, a month without swimming or sauna, and months of careful sun protection. Your own aftercare sheet sets the exact dates.
Activity rules, day by day
Sun, water, exertion, heat, alcohol and flying, for each day of a typical stay. Every rule is sourced on the day pages.
| Rule | Day 1 | Day 2 | Day 3 | Day 4 | Day 5 | Day 6 | Day 7 | Day 8 | Day 9 | Day 10 |
|---|---|---|---|---|---|---|---|---|---|---|
| Sun on the scalp | Not today | Not today | Not today | Not today | Not today | Not today | Not today | Not today | Not today | Not today |
| Swimming, sea and pools | Not today | Not today | Not today | Not today | Not today | Not today | Not today | Not today | Not today | Not today |
| Sweating and exercise | Not today | Not today | Not today | With care | With care | With care | With care | With care | With care | With care |
| Hammam, sauna and steam | Not today | Not today | Not today | Not today | Not today | Not today | Not today | Not today | Not today | Not today |
| Hats, helmets and caps | Not today | Not today | Not today | Not today | With care | With care | With care | With care | With care | With care |
| Crowds and head contact | Not today | Not today | Not today | Not today | Not today | Not today | With care | With care | With care | With care |
| Alcohol | Not today | Not today | Not today | With care | With care | With care | With care | With care | With care | With care |
| Smoking and nargile | Not today | Not today | Not today | Not today | Not today | Not today | Not today | Not today | Not today | Not today |
| Flying home | With care | OK | OK | OK | OK | OK | OK | OK | OK | OK |
✕ Not today ! With care ✓ OK
Day by day
Day 1
Most clinics see you the morning after for a check and the first wash, done by the clinic team. Grafts are at their most fragile today. Keep it short: a slow walk near the hotel and one indoor sight by taxi is plenty.
All rules for day 1, with sources
Sun on the scalp
Keep the grafted area completely out of direct sun. Use shade, indoor sights and an umbrella. Most clinics say no hat on the grafts in the first days.
Source: Smile Hair Clinic, Istanbul · Bernstein Medical
Swimming, sea and pools
No swimming of any kind. Clinic guidance ranges from 2 weeks to a month or more; the Istanbul clinic guide cited here says no swimming in the first month.
Source: Smile Hair Clinic, Istanbul · Bernstein Medical
Sweating and exercise
No exercise and nothing that makes you sweat. Short, slow walks only. Avoid bending far forward or lifting.
Source: Smile Hair Clinic, Istanbul · Bernstein Medical · NHS
Hammam, sauna and steam
Off limits. Heat and humidity soften crusts and stress the grafts. The clinic guide cited here says no sauna, steam room or hot bath for the first month.
Source: Smile Hair Clinic, Istanbul
Hats, helmets and caps
Nothing pressing on the grafts: no caps, beanies, helmets or swim caps.
Source: Bernstein Medical · Smile Hair Clinic, Istanbul
Crowds and head contact
Avoid dense crowds, low doorways and packed trams where something could knock or brush the grafts.
Source: Bernstein Medical
Smoking and nargile
No smoking for two weeks after the procedure, and better not at all. That includes nargile cafés.
Source: Bernstein Medical
Flying home
Clinic sheets allow travel and flying from around days 2 to 3. Take a neck pillow so the donor area is not pressed against the headrest, walk the aisle and drink water on long flights.
Source: Bernstein Medical · NHS
Day 2
Swelling often starts to show on the forehead between days 2 and 4. Sleep semi-upright as your clinic advised. Washing at the hotel usually starts now, using the clinic's exact method. Plan indoor, seated sights.
What changes today:
- Flying home: now OK
All rules for day 2, with sources
Sun on the scalp
Keep the grafted area completely out of direct sun. Use shade, indoor sights and an umbrella. Most clinics say no hat on the grafts in the first days.
Source: Smile Hair Clinic, Istanbul · Bernstein Medical
Swimming, sea and pools
No swimming of any kind. Clinic guidance ranges from 2 weeks to a month or more; the Istanbul clinic guide cited here says no swimming in the first month.
Source: Smile Hair Clinic, Istanbul · Bernstein Medical
Sweating and exercise
No exercise and nothing that makes you sweat. Short, slow walks only. Avoid bending far forward or lifting.
Source: Smile Hair Clinic, Istanbul · Bernstein Medical · NHS
Hammam, sauna and steam
Off limits. Heat and humidity soften crusts and stress the grafts. The clinic guide cited here says no sauna, steam room or hot bath for the first month.
Source: Smile Hair Clinic, Istanbul
Hats, helmets and caps
Nothing pressing on the grafts: no caps, beanies, helmets or swim caps.
Source: Bernstein Medical · Smile Hair Clinic, Istanbul
Crowds and head contact
Avoid dense crowds, low doorways and packed trams where something could knock or brush the grafts.
Source: Bernstein Medical
Smoking and nargile
No smoking for two weeks after the procedure, and better not at all. That includes nargile cafés.
Source: Bernstein Medical
Flying home
Clinic sheets allow travel and flying from around days 2 to 3. Take a neck pillow so the donor area is not pressed against the headrest, walk the aisle and drink water on long flights.
Source: Bernstein Medical · NHS
Day 3
Swelling is often at its peak and can reach the eyes. It looks worse than it is. Stay in cool indoor places, take taxis door to door, and keep out of crowds where someone could brush your head.
The rules are the same as yesterday.
All rules for day 3, with sources
Sun on the scalp
Keep the grafted area completely out of direct sun. Use shade, indoor sights and an umbrella. Most clinics say no hat on the grafts in the first days.
Source: Smile Hair Clinic, Istanbul · Bernstein Medical
Swimming, sea and pools
No swimming of any kind. Clinic guidance ranges from 2 weeks to a month or more; the Istanbul clinic guide cited here says no swimming in the first month.
Source: Smile Hair Clinic, Istanbul · Bernstein Medical
Sweating and exercise
No exercise and nothing that makes you sweat. Short, slow walks only. Avoid bending far forward or lifting.
Source: Smile Hair Clinic, Istanbul · Bernstein Medical · NHS
Hammam, sauna and steam
Off limits. Heat and humidity soften crusts and stress the grafts. The clinic guide cited here says no sauna, steam room or hot bath for the first month.
Source: Smile Hair Clinic, Istanbul
Hats, helmets and caps
Nothing pressing on the grafts: no caps, beanies, helmets or swim caps.
Source: Bernstein Medical · Smile Hair Clinic, Istanbul
Crowds and head contact
Avoid dense crowds, low doorways and packed trams where something could knock or brush the grafts.
Source: Bernstein Medical
Smoking and nargile
No smoking for two weeks after the procedure, and better not at all. That includes nargile cafés.
Source: Bernstein Medical
Flying home
Clinic sheets allow travel and flying from around days 2 to 3. Take a neck pillow so the donor area is not pressed against the headrest, walk the aisle and drink water on long flights.
Source: Bernstein Medical · NHS
Day 4
Swelling usually starts to ease. You can manage 2 to 3 hours of gentle sightseeing with breaks, in shade. Still nothing that makes you sweat.
What changes today:
- Sweating and exercise: now with care
- Alcohol: now with care
All rules for day 4, with sources
Sun on the scalp
Still no direct sun on the scalp. If your clinic allows it, a loose, clean, wide hat that does not touch the grafts is fine for short spells outdoors.
Source: Smile Hair Clinic, Istanbul · Bernstein Medical
Swimming, sea and pools
No swimming of any kind. Clinic guidance ranges from 2 weeks to a month or more; the Istanbul clinic guide cited here says no swimming in the first month.
Source: Smile Hair Clinic, Istanbul · Bernstein Medical
Sweating and exercise
Gentle walking with breaks. Clinics differ here: the Istanbul clinic guide says to avoid heavy sweating and heat for at least a month, while a US clinic sheet allows controlled exercise with the head held neutral from day 4. The NHS notes you may be told to cut down on exercise for the first month. Follow your own clinic.
Source: Smile Hair Clinic, Istanbul · Bernstein Medical · NHS
Hammam, sauna and steam
Off limits. Heat and humidity soften crusts and stress the grafts. The clinic guide cited here says no sauna, steam room or hot bath for the first month.
Source: Smile Hair Clinic, Istanbul
Hats, helmets and caps
Nothing pressing on the grafts: no caps, beanies, helmets or swim caps.
Source: Bernstein Medical · Smile Hair Clinic, Istanbul
Crowds and head contact
Avoid dense crowds, low doorways and packed trams where something could knock or brush the grafts.
Source: Bernstein Medical
Alcohol
The clinic sheet cited here allows alcohol again after three days. Keep it modest and ask your own clinic.
Source: Bernstein Medical
Smoking and nargile
No smoking for two weeks after the procedure, and better not at all. That includes nargile cafés.
Source: Bernstein Medical
Flying home
Clinic sheets allow travel and flying from around days 2 to 3. Take a neck pillow so the donor area is not pressed against the headrest, walk the aisle and drink water on long flights.
Source: Bernstein Medical · NHS
Day 5
Many clinics allow a loose, clean hat outdoors from around now, as long as it does not rub or press on the grafts. A seated boat trip in the shade is a good half-day.
What changes today:
- Hats, helmets and caps: now with care
All rules for day 5, with sources
Sun on the scalp
Still no direct sun on the scalp. If your clinic allows it, a loose, clean, wide hat that does not touch the grafts is fine for short spells outdoors.
Source: Smile Hair Clinic, Istanbul · Bernstein Medical
Swimming, sea and pools
No swimming of any kind. Clinic guidance ranges from 2 weeks to a month or more; the Istanbul clinic guide cited here says no swimming in the first month.
Source: Smile Hair Clinic, Istanbul · Bernstein Medical
Sweating and exercise
Gentle walking with breaks. Clinics differ here: the Istanbul clinic guide says to avoid heavy sweating and heat for at least a month, while a US clinic sheet allows controlled exercise with the head held neutral from day 4. The NHS notes you may be told to cut down on exercise for the first month. Follow your own clinic.
Source: Smile Hair Clinic, Istanbul · Bernstein Medical · NHS
Hammam, sauna and steam
Off limits. Heat and humidity soften crusts and stress the grafts. The clinic guide cited here says no sauna, steam room or hot bath for the first month.
Source: Smile Hair Clinic, Istanbul
Hats, helmets and caps
Only a loose hat your clinic approves. Helmets (bikes, scooters, quad bikes) and tight caps stay off for weeks.
Source: Bernstein Medical · Smile Hair Clinic, Istanbul
Crowds and head contact
Avoid dense crowds, low doorways and packed trams where something could knock or brush the grafts.
Source: Bernstein Medical
Alcohol
The clinic sheet cited here allows alcohol again after three days. Keep it modest and ask your own clinic.
Source: Bernstein Medical
Smoking and nargile
No smoking for two weeks after the procedure, and better not at all. That includes nargile cafés.
Source: Bernstein Medical
Flying home
Clinic sheets allow travel and flying from around days 2 to 3. Take a neck pillow so the donor area is not pressed against the headrest, walk the aisle and drink water on long flights.
Source: Bernstein Medical · NHS
Day 6
Crusts are forming and can itch. Do not scratch or pick. Light walking is fine; covered markets are better outside peak hours.
The rules are the same as yesterday.
All rules for day 6, with sources
Sun on the scalp
Still no direct sun on the scalp. If your clinic allows it, a loose, clean, wide hat that does not touch the grafts is fine for short spells outdoors.
Source: Smile Hair Clinic, Istanbul · Bernstein Medical
Swimming, sea and pools
No swimming of any kind. Clinic guidance ranges from 2 weeks to a month or more; the Istanbul clinic guide cited here says no swimming in the first month.
Source: Smile Hair Clinic, Istanbul · Bernstein Medical
Sweating and exercise
Gentle walking with breaks. Clinics differ here: the Istanbul clinic guide says to avoid heavy sweating and heat for at least a month, while a US clinic sheet allows controlled exercise with the head held neutral from day 4. The NHS notes you may be told to cut down on exercise for the first month. Follow your own clinic.
Source: Smile Hair Clinic, Istanbul · Bernstein Medical · NHS
Hammam, sauna and steam
Off limits. Heat and humidity soften crusts and stress the grafts. The clinic guide cited here says no sauna, steam room or hot bath for the first month.
Source: Smile Hair Clinic, Istanbul
Hats, helmets and caps
Only a loose hat your clinic approves. Helmets (bikes, scooters, quad bikes) and tight caps stay off for weeks.
Source: Bernstein Medical · Smile Hair Clinic, Istanbul
Crowds and head contact
Avoid dense crowds, low doorways and packed trams where something could knock or brush the grafts.
Source: Bernstein Medical
Alcohol
The clinic sheet cited here allows alcohol again after three days. Keep it modest and ask your own clinic.
Source: Bernstein Medical
Smoking and nargile
No smoking for two weeks after the procedure, and better not at all. That includes nargile cafés.
Source: Bernstein Medical
Flying home
Clinic sheets allow travel and flying from around days 2 to 3. Take a neck pillow so the donor area is not pressed against the headrest, walk the aisle and drink water on long flights.
Source: Bernstein Medical · NHS
Day 7
Crusts begin to soften with the daily washes. A full but slow day out works if you keep to shade and sit down often.
What changes today:
- Crowds and head contact: now with care
All rules for day 7, with sources
Sun on the scalp
Still no direct sun on the scalp. If your clinic allows it, a loose, clean, wide hat that does not touch the grafts is fine for short spells outdoors.
Source: Smile Hair Clinic, Istanbul · Bernstein Medical
Swimming, sea and pools
No swimming of any kind. Clinic guidance ranges from 2 weeks to a month or more; the Istanbul clinic guide cited here says no swimming in the first month.
Source: Smile Hair Clinic, Istanbul · Bernstein Medical
Sweating and exercise
Gentle walking with breaks. Clinics differ here: the Istanbul clinic guide says to avoid heavy sweating and heat for at least a month, while a US clinic sheet allows controlled exercise with the head held neutral from day 4. The NHS notes you may be told to cut down on exercise for the first month. Follow your own clinic.
Source: Smile Hair Clinic, Istanbul · Bernstein Medical · NHS
Hammam, sauna and steam
Off limits. Heat and humidity soften crusts and stress the grafts. The clinic guide cited here says no sauna, steam room or hot bath for the first month.
Source: Smile Hair Clinic, Istanbul
Hats, helmets and caps
Only a loose hat your clinic approves. Helmets (bikes, scooters, quad bikes) and tight caps stay off for weeks.
Source: Bernstein Medical · Smile Hair Clinic, Istanbul
Crowds and head contact
Grafts are better anchored, but still avoid crushes where heads and bags swing past.
Source: Bernstein Medical
Alcohol
The clinic sheet cited here allows alcohol again after three days. Keep it modest and ask your own clinic.
Source: Bernstein Medical
Smoking and nargile
No smoking for two weeks after the procedure, and better not at all. That includes nargile cafés.
Source: Bernstein Medical
Flying home
Clinic sheets allow travel and flying from around days 2 to 3. Take a neck pillow so the donor area is not pressed against the headrest, walk the aisle and drink water on long flights.
Source: Bernstein Medical · NHS
Day 8
Crusts typically fall away between days 7 and 10 with gentle washing. Redness can last for weeks and is normal.
The rules are the same as yesterday.
All rules for day 8, with sources
Sun on the scalp
Still no direct sun on the scalp. If your clinic allows it, a loose, clean, wide hat that does not touch the grafts is fine for short spells outdoors.
Source: Smile Hair Clinic, Istanbul · Bernstein Medical
Swimming, sea and pools
No swimming of any kind. Clinic guidance ranges from 2 weeks to a month or more; the Istanbul clinic guide cited here says no swimming in the first month.
Source: Smile Hair Clinic, Istanbul · Bernstein Medical
Sweating and exercise
Gentle walking with breaks. Clinics differ here: the Istanbul clinic guide says to avoid heavy sweating and heat for at least a month, while a US clinic sheet allows controlled exercise with the head held neutral from day 4. The NHS notes you may be told to cut down on exercise for the first month. Follow your own clinic.
Source: Smile Hair Clinic, Istanbul · Bernstein Medical · NHS
Hammam, sauna and steam
Off limits. Heat and humidity soften crusts and stress the grafts. The clinic guide cited here says no sauna, steam room or hot bath for the first month.
Source: Smile Hair Clinic, Istanbul
Hats, helmets and caps
Only a loose hat your clinic approves. Helmets (bikes, scooters, quad bikes) and tight caps stay off for weeks.
Source: Bernstein Medical · Smile Hair Clinic, Istanbul
Crowds and head contact
Grafts are better anchored, but still avoid crushes where heads and bags swing past.
Source: Bernstein Medical
Alcohol
The clinic sheet cited here allows alcohol again after three days. Keep it modest and ask your own clinic.
Source: Bernstein Medical
Smoking and nargile
No smoking for two weeks after the procedure, and better not at all. That includes nargile cafés.
Source: Bernstein Medical
Flying home
Clinic sheets allow travel and flying from around days 2 to 3. Take a neck pillow so the donor area is not pressed against the headrest, walk the aisle and drink water on long flights.
Source: Bernstein Medical · NHS
Day 9
You can do most low-effort sightseeing. Sun, swimming, saunas, the gym and tight hats are still off the list.
The rules are the same as yesterday.
All rules for day 9, with sources
Sun on the scalp
Still no direct sun on the scalp. If your clinic allows it, a loose, clean, wide hat that does not touch the grafts is fine for short spells outdoors.
Source: Smile Hair Clinic, Istanbul · Bernstein Medical
Swimming, sea and pools
No swimming of any kind. Clinic guidance ranges from 2 weeks to a month or more; the Istanbul clinic guide cited here says no swimming in the first month.
Source: Smile Hair Clinic, Istanbul · Bernstein Medical
Sweating and exercise
Gentle walking with breaks. Clinics differ here: the Istanbul clinic guide says to avoid heavy sweating and heat for at least a month, while a US clinic sheet allows controlled exercise with the head held neutral from day 4. The NHS notes you may be told to cut down on exercise for the first month. Follow your own clinic.
Source: Smile Hair Clinic, Istanbul · Bernstein Medical · NHS
Hammam, sauna and steam
Off limits. Heat and humidity soften crusts and stress the grafts. The clinic guide cited here says no sauna, steam room or hot bath for the first month.
Source: Smile Hair Clinic, Istanbul
Hats, helmets and caps
Only a loose hat your clinic approves. Helmets (bikes, scooters, quad bikes) and tight caps stay off for weeks.
Source: Bernstein Medical · Smile Hair Clinic, Istanbul
Crowds and head contact
Grafts are better anchored, but still avoid crushes where heads and bags swing past.
Source: Bernstein Medical
Alcohol
The clinic sheet cited here allows alcohol again after three days. Keep it modest and ask your own clinic.
Source: Bernstein Medical
Smoking and nargile
No smoking for two weeks after the procedure, and better not at all. That includes nargile cafés.
Source: Bernstein Medical
Flying home
Clinic sheets allow travel and flying from around days 2 to 3. Take a neck pillow so the donor area is not pressed against the headrest, walk the aisle and drink water on long flights.
Source: Bernstein Medical · NHS
Day 10
Most crusts are gone. Your aftercare from here is about time: no swimming or sauna for about a month and careful sun protection for months.
The rules are the same as yesterday.
All rules for day 10, with sources
Sun on the scalp
Still no direct sun on the scalp. If your clinic allows it, a loose, clean, wide hat that does not touch the grafts is fine for short spells outdoors.
Source: Smile Hair Clinic, Istanbul · Bernstein Medical
Swimming, sea and pools
No swimming of any kind. Clinic guidance ranges from 2 weeks to a month or more; the Istanbul clinic guide cited here says no swimming in the first month.
Source: Smile Hair Clinic, Istanbul · Bernstein Medical
Sweating and exercise
Gentle walking with breaks. Clinics differ here: the Istanbul clinic guide says to avoid heavy sweating and heat for at least a month, while a US clinic sheet allows controlled exercise with the head held neutral from day 4. The NHS notes you may be told to cut down on exercise for the first month. Follow your own clinic.
Source: Smile Hair Clinic, Istanbul · Bernstein Medical · NHS
Hammam, sauna and steam
Off limits. Heat and humidity soften crusts and stress the grafts. The clinic guide cited here says no sauna, steam room or hot bath for the first month.
Source: Smile Hair Clinic, Istanbul
Hats, helmets and caps
Only a loose hat your clinic approves. Helmets (bikes, scooters, quad bikes) and tight caps stay off for weeks.
Source: Bernstein Medical · Smile Hair Clinic, Istanbul
Crowds and head contact
Grafts are better anchored, but still avoid crushes where heads and bags swing past.
Source: Bernstein Medical
Alcohol
The clinic sheet cited here allows alcohol again after three days. Keep it modest and ask your own clinic.
Source: Bernstein Medical
Smoking and nargile
No smoking for two weeks after the procedure, and better not at all. That includes nargile cafés.
Source: Bernstein Medical
Flying home
Clinic sheets allow travel and flying from around days 2 to 3. Take a neck pillow so the donor area is not pressed against the headrest, walk the aisle and drink water on long flights.
Source: Bernstein Medical · NHS
Recovering abroad? Pick your city
The city guides add what to see, what to skip and where to eat on each of these days.
Hair transplant
Istanbul
10 days, day by day. Grafts are fragile for the first 7 to 10 days.
Open the guideHair transplant
Antalya
10 days, day by day. Grafts are fragile for the first 7 to 10 days.
Open the guide
Questions
Can I use sunscreen on my scalp after a hair transplant?
Not straight away. One clinic sheet allows sunscreen on the scalp from around day 10 to two weeks; another says only once your doctor confirms it, usually after the crusts have fully shed.
Is cloudy weather safe after a hair transplant?
UV gets through cloud. Treat a bright cloudy day like a sunny one in the first weeks: shade and a loose hat.
Can I wade in the sea after a hair transplant?
Some clinics allow wading without putting your head under from the end of the first week. Do not submerge your head, and keep a hat on for sun protection.
Can I go to a Turkish bath after a hair transplant?
No. The cited guidance says to avoid the sauna, steam room and hot baths completely for the first month, and ideally wait three months.
Can I wear a cap on the plane after a hair transplant?
Many patients fly home on day 2 or 3. If your clinic allows a hat that early, wear a loose one and take it off carefully, lifting straight up rather than dragging it back.
When can I wear a motorbike or bike helmet after a hair transplant?
Not during the first weeks. A helmet presses on and rubs the grafts. Ask your clinic for the date.
Questions people ask
Sources
- Sun, sea, sauna and swimming: hair transplant protection timeline. Smile Hair Clinic, Istanbul (clinic aftercare guide). Checked 2 November 2026.
- After FUT hair transplant surgery: post-op instructions. Bernstein Medical (clinic aftercare sheet). Checked 2 November 2026.
- Hair transplant. NHS (UK). Checked 2 November 2026.
- Patient information. International Society of Hair Restoration Surgery (ISHRS). Checked 2 November 2026.
- Deep vein thrombosis (DVT): long journeys. NHS (UK). Checked 2 November 2026.
- Medical tourism (CDC Yellow Book). U.S. Centers for Disease Control and Prevention. Checked 2 November 2026.