証拠の質 4.63/5
8次元のレビュー評価。基準は 品質ルーブリック 。各次元は1〜5で評価。
- D1 出典への根拠
- 4/5
- D2 出典の権威性
- 5/5
- D3 算術
- 5/5
- D4 不確実性
- 4/5
- D5 範囲
- 5/5
- D6 文章
- 5/5
- D7 認識の誠実性
- 4/5
- D8 注意事項の完全性
- 5/5
リスクはどう変わるか
見出しの数値は大きく異なる状況の平均です。シナリオや文脈による確率の違いは以下の通りです:
1,000,000分の1
No cohort has measured a respiratory-infection rate attributable to this scenario. Without an underlying viral exposure, cold feet on tile do not produce a cold. Point estimate is a structural "effectively zero" placeholder, not a measured rate.
7.1分の1 · 14%
Matches the Eccles 2005 arm: ~14% self-reported cold symptoms within 4–5 days after a 20-minute cold-foot immersion vs ~6% in controls. This is a symptom-conversion rate in an already-exposed population under a severe chilling protocol, not an infection rate from going sockless at home.
20分の1 · 5.0%
Very rough. Order of magnitude derived from WHO cold-housing guidance and UK excess-winter-mortality attribution (~21.5% of ~20,000–50,000 annual excess winter deaths → cold homes, concentrated in over-65s). The dominant pathways are cardiovascular and respiratory, not viral infection. Included as the subgroup the folk warning might actually apply to, even though it is almost never the one a grandmother has in mind when telling a child to put on slippers.
2.0分の1 · 50%
For someone with a cold-triggered vascular or cardiac condition, bare feet on cold tile reliably produces the trigger (Raynaud's episode, anginal chest pain) — but this is the underlying condition expressing itself, not a new illness. Included only to flag that "cold feet cause real symptoms" is true in this subgroup without rescuing the viral- infection folk model.
バーの長さと濃淡は、これらのシナリオを他のリスクとではなく、互いに比較して順位付けしたものです。正確な確率は各項目の横に表示されています。
暖房の効いた家の中をスリッパ、靴下、またはセーターなしで歩き回ると風邪をひくという民間信仰は、通常述べられている形ではメカニズム的に誤りであり、それを伝える人々が意図するよりもはるかに狭い形では控えめに言って正しいです。風邪はウイルスによって引き起こされ(CDCは200種類以上の異なる呼吸器ウイルスを挙げており、ライノウイルスが最も一般的です)、温度ではなく飛沫や接触によって伝染します。基礎となるウイルス曝露がなければ、タイルの上の裸足は冷たい足を生み出すだけで、他には何もありません。証拠と照合して生き残る民間モデルの部分はより狭いです。JohnsonとEccles(Cardiff, 2005)は180人を対象とした無作為化試験で、20分間の冷水に足を浸すことで、その後の4~5日間の自己申告による風邪の症状が6%から14%に増加することを示しました。また、Foxman et al.(PNAS, 2015)は、ライノウイルスが37 °Cよりも鼻腔のより冷たい33~35 °Cでよりよく複製し、自然免疫のインターフェロン反応がより弱いことを示しました。これら2つの結果は合わせて、単一の特定の主張を裏付けています。それは、冷えることが不顕性ウイルス保菌を有症状の風邪に転換させる可能性があるということです。これらは、寒冷曝露が何もないところから病気を引き起こすという主張を裏付けるものではありません。
この特定の恐怖について興味深いのは、それが指し示すシナリオと、家の中の寒さが実際に人々を死に至らしめるシナリオとの間の隔たりです。民間での警告は通常、暖房の効いた家の中にいる健康な子供や大人(スリッパを履きなさい、冷たいタイルに座らないで、濡れた髪で歩き回らないで)に対して発せられますが、そこではEcclesの変調効果が証拠が許容する範囲の天井であり、それに起因する冬ごとの感染率を測定しようとしたコホートはありません。屋内の寒さが明確に致命的となるシナリオは、ほぼ逆の人口統計です。それは、WHOの2018年住宅と健康ガイドラインおよび英国ONSの冬季超過死亡率データが、年間20,000~50,000人の冬季超過死亡のうち約21.5%が寒冷な住宅に起因すると特定している、16~18 °C以下に保たれた家に住む虚弱な高齢者です。主な原因は循環器疾患と呼吸器疾患です。その害は、周囲の室温と血管ストレスに関するものであり、靴下を忘れることに関するものではありません。
「無視できる」という枠組みが当てはまらない場合:レイノー現象を持つ人は、感染の有無にかかわらず、冷たいタイルから確実に発作を引き起こします。また、寒冷誘発性狭心症は、感受性の高い人にとっては実際の心臓イベントです。呼吸器ウイルスを保菌している免疫不全の読者は、一般人口のベースラインよりもEcclesの14%群に近い位置にあるかもしれませんが、その研究はそのように述べるほどの検出力はありませんでした。寒冷な住宅での死亡率データと一致させるために民間での警告が向けられるべき特定のサブグループ(特に既存の心肺疾患を持つ、暖房が不十分な住宅に住む虚弱な高齢者や乳幼児)は、通常、実際に警告を受けているサブグループではありません。スリッパに関する助言は、ほとんどの場合、正しい文化的本能が間違った曝露に向けられているものです。
関連する豆知識
雨の中を歩いても風邪はひかない。冷たい表面に座っても膌胱炎にはならない。薄着で家にいても病気にはならない。ウイルスが感染症を引き起こす。温度は引き起こさない。
根拠台帳
以下の各数値は各出典が報告した内容であり、引用した原文の抜粋と算出方法を記載しています。リンクをクリックして直接確認できます。
2/5 件の出典が引用元と一字一句一致することを独立して検証済み
-
[1] Family Practice (Oxford Academic), via PubMed — Acute cooling of the feet and the onset of common cold symptoms
Acute cooling of the feet and the onset of common cold symptomsSee all 3 Likelier entries citing this source →
- 統計値
13/90 chilled subjects vs 5/90 controls self-reported cold symptoms in the 4–5 days after a 20-minute cold-foot immersion (P=0.047)- 抜粋
“"There is a common folklore that chilling of the body surface causes the development of common cold symptoms, but previous clinical research has failed to demonstrate any effect of cold exposure on susceptibility to infection with common cold viruses. [...] 13/90 subjects who were chilled reported they were suffering from a cold in the 4/5 days after the procedure compared to 5/90 control subjects (P=0.047). [...] Acute chilling of the feet causes the onset of common cold symptoms in around 10% of subjects who are chilled. Further studies are needed to determine the relationship of symptom generation to any respiratory infection." ”
- 出典データ
- 2005-12-01
- アクセス日
- 2026-04-16 · アーカイブ版
- 計算過程
- This is the canonical trial behind any "cold feet causes colds" claim. Critical qualifier the authors themselves flag: the study measured self-reported symptoms, not laboratory-confirmed new infections. The plausible mechanism the authors propose is that reflex vasoconstriction in the upper airway on cold- foot exposure reduces mucosal blood flow and temporarily lowers local defences — converting a pre-existing subclinical carriage of rhinovirus or another respiratory virus into a symptomatic cold. That is a modulation effect, not a causation effect. Without an underlying viral exposure, cooling the feet is not expected to produce illness from nothing. 90 subjects per arm gives an absolute difference of 8 percentage points (14% vs 6%); the confidence bound is wide, and no replication of comparable rigour exists at the scale needed to attach a per-winter probability to "no slippers at home."
- 独立性
- Independent single-centre RCT at Cardiff (Common Cold Centre); editorially independent of the CDC and WHO sources. The Foxman 2015 mechanistic paper below provides a biological model compatible with Eccles' clinical result but was conducted in a separate lab with different methodology (mouse airway cells, not human subjects).
-
[2] Proceedings of the National Academy of Sciences (PNAS), via PubMed — Temperature-dependent innate defense against the common cold virus limits viral replication at warm temperature in mouse airway cells 検証済み
Temperature-dependent innate defense against the common cold virus limits viral replication at warm temperature in mouse airway cellsSee all 2 Likelier entries citing this source →
- 統計値
Rhinovirus replicates more robustly at 33–35 °C (nasal cavity) than at 37 °C (core body), with weaker interferon/antiviral response at the cooler temperature- 抜粋
“"Most isolates of human rhinovirus, the common cold virus, replicate more robustly at the cool temperatures found in the nasal cavity (33–35 °C) than at core body temperature (37 °C). [...] These findings demonstrate that in mouse airway cells, rhinovirus replicates preferentially at nasal cavity temperature due, in part, to a less efficient antiviral defense response of infected cells at cool temperature." ”
- 出典データ
- 2015-01-20
- アクセス日
- 2026-04-16 · アーカイブ版
- 検証
- グラウンディング監査の際、抜粋を引用元から独立して再取得し、原文と一字一句一致することを確認しました。
- 計算過程
- Foxman et al. supplies the cleanest known mechanism for any cold-exposure- to-cold-illness signal: rhinovirus itself replicates better in a cooler nose, and the innate interferon response is weaker at 33 °C than at 37 °C. This makes Eccles' symptom-onset result biologically plausible without rescuing the folk model. The study is mouse airway cells in vitro, not an epidemiological measurement, and no study has translated the temperature- dependent replication curve into a per-exposure infection probability for a human wearing socks versus going barefoot. The mechanism is real; the epidemiological effect size at normal indoor conditions is not quantified.
- 独立性
- Yale laboratory study with no authorship, funding, or institutional overlap with the Cardiff Eccles group; treat as methodologically independent mechanistic corroboration. Independent of the CDC and WHO sources.
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[3] US Centers for Disease Control and Prevention — About the Common Cold
About the Common ColdSee all 2 Likelier entries citing this source →
- 統計値
More than 200 respiratory viruses cause colds; rhinoviruses are the most frequent cause; primary spread is droplets and contact- 抜粋
“"More than 200 respiratory viruses can cause colds. Rhinoviruses are the most frequent cause of colds in the United States. [...] Most respiratory viruses are spread through droplets that an infected person releases when they cough or sneeze. These droplets can enter your body if you breathe them in or touch a contaminated surface and then touch your eyes, nose, or mouth." ”
- 出典データ
- 2026-02-19
- アクセス日
- 2026-04-16 · アーカイブ版
- 計算過程
- CDC's current patient-facing page is the plain-language anchor for the "colds are viral, not thermal" frame. The folk model treats cold exposure as causative; CDC treats virus exposure as causative and does not list chilling or being under-dressed indoors as a transmission route at all. The Eccles and Foxman results sit downstream of this: you still need the virus. Without rhinovirus or one of the other ~200 candidates in your airway, cold feet on tile do not produce a cold.
- 独立性
- Institutional CDC public-health guidance; editorially independent of the Eccles clinical trial and Foxman mechanistic paper, though it aligns with both.
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[4] World Health Organization (via NCBI Bookshelf) — Low indoor temperatures and insulation — WHO Housing and Health Guidelines 検証済み
Low indoor temperatures and insulation — WHO Housing and Health Guidelines- 統計値
WHO recommends minimum indoor temperature of 18 °C to protect general populations; higher minimum for vulnerable groups (older people, children, chronic cardiorespiratory illness)- 抜粋
“"For countries with temperate or colder climates, 18 °C has been proposed as a safe and well-balanced indoor temperature to protect the health of general populations during cold seasons. [...] A higher minimum indoor temperature than 18 °C may be necessary for vulnerable groups including older people, children and those with chronic illnesses, particularly cardiorespiratory disease." ”
- 出典データ
- 2018-11-27
- アクセス日
- 2026-04-16 · アーカイブ版
- 検証
- グラウンディング監査の際、抜粋を引用元から独立して再取得し、原文と一字一句一致することを確認しました。
- 計算過程
- WHO's guideline is the authoritative carve-out for the one scenario in which "being under-dressed at home" really does kill people: under-heated housing in cold climates, especially for the elderly and those with cardiorespiratory disease. The exposure here is the ambient indoor temperature (below ~18 °C sustained), not a barefoot afternoon in a heated 21 °C living room. The outcome is cardiovascular and respiratory morbidity and mortality, not the common cold. This is the reason the headline framing ("folk belief overrated") must be paired with an explicit vulnerable-group caveat rather than a blanket dismissal.
- 独立性
- WHO expert consensus guideline synthesising the cold-housing evidence base. Editorially independent of the Eccles, Foxman, and CDC sources and addresses a distinct exposure-outcome pair (sustained low ambient temperature → cardiovascular/respiratory death), not symptom onset of the common cold.
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[5] UK Parliamentary Office of Science and Technology — Winter mortality (POSTnote 752)
Winter mortality (POSTnote 752)- 統計値
Excess winter deaths in England and Wales ranged ~20,000–50,000/year 2000–2019; ~21.5% of excess winter deaths attributable to cold homes; most deaths from circulatory or respiratory disease among the elderly- 抜粋
“"Between 2000 and 2019, excess winter deaths ranged from 20,000 to 50,000 a year [...] Most excess winter deaths are due to circulatory or respiratory diseases and the majority occur amongst the elderly population. [...] It has been estimated that 10% of excess winter deaths are attributable to fuel poverty and 21.5% to cold homes." ”
- 出典データ
- 2024-01-01
- アクセス日
- 2026-04-16 · アーカイブ版
- 計算過程
- This is the population-scale number for the one real cold-in-the-home harm: under-heated housing kills elderly people through cardiovascular and respiratory pathways, not through infection. It does not apply to the folk-belief scenario (healthy adult, barefoot in a warm house) and should not be aggregated with the Eccles symptom-onset figure. Used here only to bound the vulnerable-group subgroup in the regional breakdown and to keep the caveats honest about who the folk warning, repurposed, actually applies to.
- 独立性
- UK Parliament research briefing drawing on ONS winter-mortality data and NICE fuel-poverty reviews. Editorially independent of the WHO guideline (though it references the same underlying epidemiology) and independent of the Eccles, Foxman, and CDC sources.