Fact check: No risk of temperature shock when bathing, drinking cold water in hot weather

MANILA, Philippines — The Department of Health said on Wednesday it is safe for individuals to cool their bodies down and drink cold water right after being outdoors in 40°C weather, contrary to a viral Facebook post claiming otherwise. 

Department of Health Officer-in-Charge Maria Rosario Vergeire said in a media forum on Monday that a viral chain message claiming that those exposed to extremely warm weather need to wait 30 minutes before bathing to avoid health complications is “not true.”

CLAIM: Several Facebook users have been reposting the same advisory claiming that drinking cold water when outdoor temperatures hit 38 to 40°C will make their blood vessels burst. The advisory also claimed that people exposed to hot weather need to wait 30 minutes before bathing in cold water to avoid health risks.

RATING: This is false. 

FACTS:

What the post says

Several Facebook accounts started reposting the same claim starting March 21 – the same day the Philippines’ state weather bureau declared the start of the dry season – according to social media monitoring tool CrowdTangle

Warning of a supposed “heat wave” about to take place in the Philippines, the viral advisory stated: “Sabi ng mga doctor kapag ang temperatura ay umabot na sa 40°C, huwag agad2 uminom ng napakalamig na tubig sapagkat ang maliliit nating ugat ng dugo ay maaaring pumutok o sumabog (Doctors said that if the temperature reaches 40°C, you should not drink cold water right away because our small blood vessels could burst).”

The post also stated that a “friend” who is also a doctor collapsed and was rushed to a hospital after washing their feet in cold water to cool their body down from the hot weather.

The post also claimed that an individual’s body needs to cool down for 30 minutes after being outside in 38°C weather:

“Kapag umabot na sa 38°C ang init at galing kayo sa labas.. hayaan natin na mainit ang ating katawan… Huwag kaagad maghugas ng kamay o paa, wag maghilamos o basain ang bahaging nabilad sa araw. Magpalipas ng di bababa sa 30 minuto o kalahating oras bago maghilamos o maligo (When the weather reaches 38°C and you just came from outside, let your body stay warm… Don’t immediately wash your hands or your feet, don’t wash your face or parts of your body exposed to the sun. Let 30 minutes pass before washing your body or bathing).” 

The post added that during the warm season or when one feels exhausted, they should avoid drinking cold water, which will cause blood vessels to burst or cause a stroke. 

A certain “Kuya Caloy Z. Reyes” also translated the post into Filipino, the post stated. 

“Please share it and save a life,” the post added.

What the posts left out

Bathing is the “most effective” way to cool the body down after exposure to warm weather, Vergeire said.

“What we do (through bathing) is… we cool down the body, and the most effective (way) to do that is to give the patient a shower,” Vergeire said in Filipino. 

Vergeire added that as long as the person is conscious and can stand, they can bathe with cold water to cool their body down.  

Blood vessels also “do not explode on exposure to cold,” according to neurologist Jose Paciano Reyes, who was quoted in a VERA Files fact-check in May 2021 debunking the same claim.

According to Paciano, “the opposite actually happens: the physiologic response to cold exposure causes skin blood vessels to constrict to conserve heat.” the VERA Files fact-check article stated.

While Vergeire said that it is safe for persons exposed to heat to drink cold water "in sips," she added a disclaimer that people suddenly drinking cold water after direct exposure to the sun could cause headaches. 

Essential context

The Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA)  has advised the public “to take precautionary measures to minimize heat stress” during the dry season.

More than 100 students in a Laguna school last week had to be rushed to the hospital after experiencing heat exhaustion during a fire drill held on campus, prompting the DOH and DepEd to look into the incident. The heat index at the time was between 39 to 42 degrees Celsius.

Why we fact-checked this  

At least 64 Facebook pages and accounts have reposted the claim as of press time. Most of these are unverified Facebook pages representing residents of a city or a province, while others are unverified pages related to DepEd school divisions, according to social media monitoring tool CrowdTangle.

Facebook page Sigaw Ng Bataan, which has around 48,000 followers, reached the most number of shares and reactions among the Facebook accounts that reposted the claim. Its post gathered more than 400 shares, 200 reactions and 30 comments.  

ABS-CBN also debunked a similar claim in 2019.