Sauna bathing and mortality risk: unraveling the interaction with systolic blood pressure in a cohort of Finnish men.

Objectives: This cohort study aimed to investigate the potential interplay between systolic blood pressure (SBP), frequency of sauna bathing (FSB), and all-cause mortality risk among Caucasian men. Design: A prospective study was conducted, involving 2575 men aged 42 to 61 years. Baseline assessments included resting blood pressure measurements and self-reported sauna bathing habits. SBP levels were categorized as normal (<140 mmHg) or high (≥140 mmHg), while FSB was classified as low (≤2 sessions/week) or high (3-7 sessions/week). Hazard ratios (HRs) with 95% confidence intervals (CIs) were estimated using Cox regression analysis, while adjusting for lifestyle factors, lipids, inflammation, and comorbidities. Results: Over a median follow-up of 27.8 years, 1,618 deaths were recorded. In the adjusted analysis, individuals with high SBP versus low SBP showed a 29% increased all-cause mortality risk (HR 1.29, 95% CI 1.16-1.43). Similarly, those with low FSB versus high FSB exhibited a 16% elevated mortality risk (HR 1.16, 95% CI 1.02-1.31). When considering combined effects, participants with high SBP-low FSB had a 47% higher mortality risk (HR 1.47, 95% CI 1.24-1.74) compared to those with normal SBP-high FSB. However, no significant association was observed between individuals with high SBP-high FSB and mortality risk (HR 1.24, 95% CI 0.98-1.57). There were potential additive and multiplicative interactions between SBP and sauna bathing concerning mortality risk. Conclusions: This study reveals a potential interplay between SBP, sauna bathing, and mortality risk in Finnish men. Frequent sauna bathing may mitigate the increased mortality risk associated with elevated SBP.

Effects of regular sauna bathing in conjunction with exercise on cardiovascular function: a multi-arm, randomized controlled trial.

Regular exercise and sauna bathing have each been shown to improve cardiovascular function in clinical populations. However, experimental data on the cardiovascular adaptations to regular exercise in conjunction with sauna bathing in the general population are lacking. Therefore, we compared the effects of exercise and sauna bathing to regular exercise using a multi-arm randomized controlled trial. Participants (n = 47) aged 49 ± 9 with low physical activity levels and at least one traditional cardiovascular disease (CVD) risk factor were randomly assigned (1:1:1) to guideline-based regular exercise and 15-min postexercise sauna (EXS), guideline-based regular exercise (EXE), or control (CON) for 8 wk. The primary outcomes were blood pressure (BP) and cardiorespiratory fitness (CRF). Secondary outcomes included fat mass, total cholesterol levels, and arterial stiffness. EXE had a greater change in CRF (+6.2 mL/kg/min; 95% CI, +4.2 to +8.3 mL/kg/min) and fat mass but no differences in BP when compared with CON. EXS displayed greater change in CRF (+2.7 mL/kg/min; 95% CI, +0.2 to +5.3 mL/kg/min), lower systolic BP (-8.0 mmHg; 95% CI, -14.6 to -1.4 mmHg), and lower total cholesterol levels compared with EXE. Regular exercise improved CRF and body composition in sedentary adults with CVD risk factors. However, when combined with exercise, sauna bathing demonstrated a substantially supplementary effect on CRF, systolic BP, and total cholesterol levels. Sauna bathing is a valuable lifestyle tool that complements exercise for improving CRF and decreasing systolic BP. Future research should focus on the duration and frequency of exposure to ascertain the dose-response relationship.

Death in Sauna Associated With a Transdermal Fentanyl Patch.

We present a case of an accidental fatal fentanyl overdose caused by increased uptake of the drug from a transdermal patch while experiencing the heat of a sauna.The transdermal patch administers fentanyl at a relatively constant rate through the skin. However, in the subcutaneous tissue, blood circulation greatly influences the rate of this drug's systemic intake. In the present case, an elderly woman with multiple health conditions was prescribed fentanyl patches but was unaware of the risks associated with external heat sources when one wears the patch. She was found dead in the sauna with a postmortem femoral blood concentration of fentanyl that was elevated (15 µg/L). The cause of death was determined to be fatal poisoning by fentanyl with the contributing factor of external heat from the sauna.Risks associated with transdermal administration of a potent opioid-like fentanyl are widely described in the scientific literature and described in the manufacturer's summary of product characteristics. Physicians and pharmacists should take particular care to ensure that patients understand these risks.

Fatal α-PVP and amphetamine poisoning during a sauna and autoerotic practices.

We describe the sudden death of a middle-aged man while having a sauna under the influence of α-pyrrolidinovalerophenone (α-PVP) (PM blood concentration: 0.8 mg/L), amphetamine (0.34 mg/L), and other drugs (buprenorphine, benzodiazepines), and engaging in solitary sexual activities. The drugs' effects on the cardio-circulatory system and on body thermoregulation combined with the high temperatures are likely to have been central mechanisms leading to death. The high levels of adrenaline triggered by sexual arousal and the respiratory depression caused by buprenorphine, in association with benzodiazepines, may have also contributed to his death. This previously unreported type of accidental autoerotic death illustrates the risk of using amphetamine-like sympathomimetic drugs (e.g. cathinone derivates) in hot environments such as a sauna, and during sexual activities therein.

Sauna bathing and systemic inflammation.

We aimed to investigate whether frequency of sauna bathing is associated with the levels of serum C-reactive protein. C-reactive protein is a leading blood marker of systemic inflammation. The study consisted of 2084 men (42-60 years) without acute or chronic inflammation. A total of 533 (25.6%), 1368 (65.6%), and 183 (8.8%) participants reported having a sauna bath once a week, 2-3 times, and 4-7 times per week; mean serum C-reactive protein levels were 2.41 (standard deviation 2.91), 2.00 (2.41), 1.65 (1.63) mmol/L, respectively. In a multivariable analysis adjusted for baseline age, body mass index, systolic blood pressure, smoking, type 2 diabetes, previous myocardial infarction, and serum low density lipoprotein cholesterol, alcohol consumption and physical activity, there was a significant inverse association between the frequency of sauna bathing and the level of C-reactive protein. Further studies are warranted to investigate the relationship between sauna bathing and systemic inflammation.

Sauna Bathing and Risk of Psychotic Disorders: A Prospective Cohort Study.

OBJECTIVE: Sauna bathing has been suggested to promote mental well-being and relaxation, but the evidence is uncertain with respect to mental disorders. We aimed to assess the association of frequency of sauna bathing with risk of psychosis in the Kuopio Ischemic Heart Disease prospective population-based study. SUBJECTS AND METHODS: Baseline sauna bathing habits were assessed in 2,138 men aged 42-61 years who had no history of psychotic disorders. Participants were classified into three groups based on the frequency of sauna bathing (once, 2-3, and 4-7 times per week). RESULTS: During a median follow-up of 24.9 years, 203 psychotic disorders were recorded. A total of 537, 1,417, and 184 participants reported having a sauna bath once a week, 2-3 times, and 4-7 times per week, respectively. In Cox regression analysis adjusted for age, compared to men who had 1 sauna session per week, the hazard ratio (95% confidence intervals) of psychosis for 4-7 sauna sessions per week was 0.23 (0.09-0.58). In a multivariable model adjusted for several risk factors and other potential confounders, the corresponding hazard ratio was 0.21 (0.08-0.52). The association was similar after further adjustment for total energy intake, socioeconomic status, physical activity, and C-reactive protein (0.22 [0.09-0.54]) and was unchanged on additional adjustment for duration of a sauna session and temperature of the sauna bath (0.23 [0.09-0.57]). CONCLUSION: Our study suggests a strong inverse and independent association between frequent sauna bathing and the future risk of psychotic disorders in a general male population.

Extreme Rapid Weight Loss and Rapid Weight Gain Observed in UK Mixed Martial Arts Athletes Preparing for Competition.

There is a lack of research documenting the weight-making practices of mixed-martial-arts (MMA) competitors. The purpose of the investigation was to quantify the magnitude and identify the methods of rapid weight loss (RWL) and rapid weight gain (RWG) in MMA athletes preparing for competition. Seven athletes (mean ± SD, age 24.6 ± 3.5 yrs, body mass 69.9 ± 5.7 kg, competitive experience 3.1 ± 2.2 yrs) participated in a repeated-measures design. Measures of dietary intake, urinary hydration status, and body mass were recorded in the week preceding competition. Body mass decreased significantly (p < .0005) from baseline by 5.6 ± 1.4 kg (8 ± 1.8%). During the RWG period (32 ± 1 hr) body mass increased significantly (p < .001) by 7.4 ± 2.8 kg (11.7 ± 4.7%), exceeding RWL. Mean energy and carbohydrate intake were 3176 ± 482 kcal・day-1 and 471 ± 124 g・day-1, respectively. At the official weigh-in 57% of athletes were dehydrated (1033 ± 19 mOsmol・kg-1) and the remaining 43% were severely dehydrated (1267 ± 47 mOsmol・kg-1). Athletes reported using harmful dehydration-based RWL strategies, including sauna (43%) and training in plastic suits (43%). Results demonstrated RWG greater than RWL, this is a novel finding and may be attributable to the 32 hr duration from weigh-in till competition. The observed magnitude of RWL and strategies used are comparable to those which have previously resulted in fatalities. Rule changes which make RWL impractical should be implemented with immediate effect to ensure the health, safety and wellbeing of competitors.

Effect of sauna-based heat acclimation on plasma volume and heart rate variability.

PURPOSE: We investigated the effect of post-exercise sauna bathing on plasma volume (PV) expansion and whether such responses can be tracked by changes in heart rate (HR)-based measures. METHODS: Seven, well-trained male cyclists were monitored for 35 consecutive days (17 days baseline training, 10 days training plus sauna, 8 days training). Sauna exposure consisted of 30 min (87 °C, 11 % relative humidity) immediately following normal training. Capillary blood samples were collected while resting seated to assess PV changes. HR (HRwake) and vagal-related HR variability (natural logarithm of square root mean squared differences of successive R-R intervals, ln rMSSDwake) were assessed daily upon waking. A sub-maximal cycle test (5 min at 125 W) was performed on days 1, 8, 15, 22, 25, 29, and 35 and HR recovery (HRR60s) and ln rMSSDpostex were assessed post-exercise. Effects were examined using magnitude-based inferences. RESULTS: Compared with baseline, sauna resulted in: (1) peak PV expansion after four exposures with a likely large increase [+17.8 % (90 % confidence limits, 7.4; 29.2)]; (2) reduction of HRwake by a trivial-to-moderate amount [-10.2 % (-15.9; -4.0)]; (3) trivial-to-small changes for ln rMSSDwake [4.3 % (1.9; 6.8)] and ln rMSSDpostex [-2.4 % (-9.1; 4.9)]; and (4) a likely moderate decrease in HRR60s [-15.6 % (-30.9; 3.0)]. Correlations between individual changes in PV and HR measures were all unclear. CONCLUSIONS: Sauna bathing following normal training largely expanded PV in well-trained cyclists after just four exposures. The utility of HR and HRV indices for tracking changes in PV was uncertain. Future studies will clarify mechanisms and performance benefits of post-training sauna bathing.

[Sauna deaths in Hesse, Germany, between 1994 and 2014]. / Saunatodesfälle in Hessen 1994-2014.

Due to the high ambient temperature, sauna deaths show a few confounding particularities, such as an accelerated onset of the postmortem changes, that can make correct assessment of the manner of death difficult and severely constrain the accuracy of post- mortem interval estimates. This retrospective study, performed at the medicolegal institutes in Hesse, Germany, reviewed all autopsy reports from the years 1994-2014 for sauna-related deaths. 9 relevant cases were found involving one woman and eight men aged between 52 and 80 years (mean and median value: 67 years). Of the individuals who had died of a natural cause, four were found to have had coronary heart disease, which, in the setting of heart hypertrophy and exposure to high temperatures, ultimately led to cardiac failure. In three other cases, a non-natural cause of death had been diagnosed; however, all were attributable to accidents. In two of these, blood alcohol concentrations (BAC) of over two per mil were found. In our opinion, the manner of death should be classified as undetermined in sauna-related fatalities. Such cases require a court-ordered autopsy to reliably identify the actual cause of death.

New type of sauna-related burn: conductive contact burn.

A 70-year-old woman visited a Korean-style hot dry sauna room. The patient had a medical history of hypertension and hyperlipidemia. During the sauna, the patient slept for 30 minutes. During the sleep, the right medial thigh was covered with a fully wet towel. The patient sustained a second-degree burn on the right medial thigh area with multiple bullas. On physical examination, erythema, heating sensation, and swelling around the bullas were noted. The patient was admitted and received intravenous antibiotics for 7 days. A dressing with Silmazine 1% cream (sulfadiazine) was applied twice a day for prevention of local infection. The patient was discharged on day 14 without complication. In this case, the mechanism of the burn was different. Hot air has much thermal energy but is not conducted to the skin directly. A wet towel will have a relatively higher thermal capacity or heat capacity than a dry or damp towel, and the sodden water might be a medium for the conduction of thermal energy. Owing to the global popularity of sauna bathing, it is important to recognize all sources of sauna-related burns.

[Three cases of external auditory exostoses in a habitual sauna user].

Exostoses are benign bony excrescences of the external auditory canal, commonly encountered in people who avidly engage in aquatic activities, hence the name "surfer's ear". Exostoses are more prevalent in cold water surfers, and additional years of surfing increase one's risk not only for developing an exostosis but also for developing more severe lesions. Exostoses remain clinically silent until they become large enough to impair the egress of epithelial debris and water from the canal, in which case there may be an associated external otitis and fluctuating hearing loss. Histologically, they demonstrate a laminated structure consistent with a periodic growth pattern. They may also cause a hearing loss by impinging upon the tympanic membrane and manubrium. Symptomatic relief is attained by surgical removal and skin grafting of the epithelially denuded areas of the bony walls of the external auditory canal. We report herein on 3 cases of exostoses which developed in patients who had a habit of taking a cold water bath after a hot sauna for more than 15 years: in spite of the limited time of exposure to cold water stimulation, alternating exposure to the hot environment of the sauna and cold water baths seemed to have acceralated the formation of the exostoses.

Injuries related to sauna bathing.

PURPOSE: Awareness of well-being and health issues have contributed to increased popularity of sauna bathing. However, little is known about potential risks and injuries. The aim of this study was to identify the causes for injuries, the affected body regions and to define recommendations for prevention. METHODS: A retrospective chart data analysis was conducted among patients treated for an injury related to sauna bathing at the local trauma centre of the Medical University of Innsbruck between January 1, 2005 and December 31, 2021. Patients' demographics, the cause for the injury, the diagnosis, the body region of the trauma and the treatment methods were collected. RESULTS: Two hundred and nine patients with injuries related to sauna bathing (83 female [39.7%] and 126 male [60.3%]) were identified. Fifty-one patients showed more than one injuries leading to a total of 274 diagnosis: contusions/distorsions (113; 41.2%), wounds (79; 28.8%), fractures (42; 15.3%), ligament injuries (17; 6.2%), concussions (15; 5.5%), burns (4; 1.5%) and brain bleeding (3; 1.1%). The most common cause for an injury was a slip/fall (157; 57.5%) followed by dizziness/syncope (82; 30.0%). Interestingly, head and face injuries were mostly caused by dizziness/syncope, whereas slip/fall was the leading cause for injuries of foot, hand, forearm and wrist. Nine patients(4.3%) needed surgical treatment mainly due to fractures. Eight patients got injured by wood splinters. One patient sustained grade IIB-III burns lying unconscious with an alcohol intoxication of 3.6‰ in the sauna. CONCLUSION: The main causes for injuries during sauna bathing were slip/falls and dizziness/syncopes. The latter one might be prevented by improved of the personal behaviour (e.g. drink enough water before and after each sauna bathing), whereas slip/falls might be prevented by the revision of safety regulations, particularly the obligation to wear slip resistant slippers. Thus, everyone himself as well as the operators can contribute to reduce injuries related sauna bathing.

Sauna contact burns in adults in the Helsinki Burn Centre during 2006-2018.

INTRODUCTION: Within Finish culture is a strong tradition of sauna bathing. This special environment predisposes the persons refreshing in the sauna to different kind of burns with varying etiologies. Despite the high prevalence of sauna related burns in Finland, there is paucity on the sauna related burns literature. METHODS: In this 13-year retrospective study, all sauna-related contact burns in the adult population treated at the Helsinki Burn Centre were analyzed. Altogether 216 patients were included in this study. RESULTS: The incidence of sauna-related contact burns was significantly higher in males; they accounted for 71.8% of patients. In addition to male gender, another risk factor was high age, with the elderly also being more prone to have a longer length of stay in hospital and more often receiving operative treatment. Despite most burns being relatively small, they were deep and more than one-third (36.6%) of patients underwent surgery. A strong seasonal variation in the injuries was recorded; over 40% of the burns took place during the summer months. CONCLUSION: Sauna contact burns are common, and despite their small size, they frequently cause deep injuries indicating operative treatment. There is a clear male predominance in the patient population. Most probably the cultural aspects of sauna bathing at summer cottages explain the strong seasonal variation in the incidence of these burns. The long latency between initial injury and presentation at the Helsinki Burn Centre should be highlighted to health care centres and central hospitals.

The Interplay between Systolic Blood Pressure, Sauna Bathing, and Cardiovascular Mortality in Middle-Aged and Older Finnish Men: A Cohort Study.

OBJECTIVES: Elevated systolic blood pressure (SBP) is associated with an increased risk of cardiovascular disease (CVD) mortality, whereas frequent sauna bathing reduces the risk. Whether frequent sauna bathing mitigates CVD mortality among adults with elevated SBP has not been previously investigated. DESIGN AND SETTING: We examined the interactions between SBP and frequency of sauna bathing (FSB) with the risk of CVD mortality in a cohort of Caucasian men. PARTICIPANTS: The Kuopio Ischaemic Heart Disease Study cohort comprising of 2,575 men aged 42-61 years at baseline was employed for this prospective study analysis. MEASUREMENTS: Resting blood pressure was measured using a standardized protocol and sauna bathing habits were assessed by a self-administered questionnaire. Systolic blood pressure was categorized as normal and high (<140 and ≥140 mmHg, respectively) and FSB as low and high (defined as ≤ 2 and 3-7 sessions/week, respectively). RESULTS: A total of 744 CVD deaths were recorded during a median follow-up of 27.8 yr. Comparing high vs normal SBP, the multivariable-adjusted HR (95% CI) for CVD mortality was 1.44 (1.23-1.68). Comparing low vs high FSB, the multivariable-adjusted HR (95% CI) for CVD mortality was 1.24 (1.03-1.51). The associations persisted following mutual adjustment for each exposure. Compared with men with normal SBP-high FSB, high SBP-low FSB was associated with an increased risk of CVD mortality 1.81 (1.39-2.36), with attenuated but persisting evidence of an association for men with high SBP and high FSB 1.52 (1.06-2.16). When SBP was categorized as normal and high (<130 and ≥130 mmHg, respectively), there was no evidence of an association for men with high SBP and high FSB 1.11 (0.77-1.61). CONCLUSION: There might be an interaction between SBP, sauna bathing and CVD mortality risk in middle-aged and older Caucasian males. Frequent sauna baths may offset the increased risk of CVD mortality in men with high-normal SBP but not elevated SBP.

Does the Combination of Finnish Sauna Bathing and Other Lifestyle Factors Confer Additional Health Benefits? A Review of the Evidence.

Sauna bathing, a tradition deeply rooted in the Finnish culture, has been used for thousands of years for leisure, relaxation, and wellness. Sauna bathing is linked with substantial health benefits beyond its use for leisure and relaxation. Several observational and interventional studies suggest that regular or frequent sauna bathing reduces the incidence of vascular and nonvascular diseases, such as hypertension, cardiovascular disease, dementia, and respiratory conditions; may improve the severity of conditions such as musculoskeletal disorders, COVID-19, headache, and influenza; and increases the life span. The beneficial effects of sauna bathing on adverse outcomes have been linked to its blood pressure-reducing, anti-inflammatory, antioxidant, cytoprotective, and stress-reducing properties and its synergistic effect on neuroendocrine, circulatory, cardiovascular, and immune function. Evidence suggests that frequent sauna bathing is an emerging protective risk factor that may augment the beneficial effects of other protective risk or lifestyle factors, such as physical activity and cardiorespiratory fitness, or attenuate or offset the adverse effects of other risk factors, such as high blood pressure, systemic inflammation, and low socioeconomic status. This review summarizes the available epidemiologic and interventional evidence linking the combined effects of Finnish sauna bathing and other risk factors on vascular outcomes including cardiovascular disease and intermediate cardiovascular phenotypes, nonvascular outcomes, and mortality. We also discuss the mechanistic pathways underlying the joint contributions of Finnish sauna bathing and other risk factors on health outcomes, the public health and clinical implications of the findings, gaps in the existing evidence base, and future directions.

Acute liver failure due to non-exertional heatstroke after sauna.

Acute liver failure is defined as rapid loss of liver function that patients without previously recognized liver disease sustain a liver damage. Acute liver failure due to non-exertional heatstroke has rarely been reported. We reported here an unusual case of heat stroke induced acute liver failure (ALF) after sauna. A 63 year old man without previously recognized liver and other systemic disease was admitted for loss of consciousness and impaired liver function after sauna. Despite intensive supportive care, ALF developed. Liver transplantation was planned but the patient died on the sixth day of hospitalization. Non-exertional heatstroke induced ALF is a rare and serious condition. ALF caused by non-exertional heatstroke which requires liver transplantation for definitive solution should be kept in mind in early period.

Frequent sauna bathing offsets the increased risk of death due to low socioeconomic status: A prospective cohort study of middle-aged and older men.

BACKGROUND AND AIM: Low socioeconomic status (SES) and frequent sauna bathing are associated with increased and decreased risk of all-cause mortality, respectively. Whether there is an interplay among SES, sauna bathing and all-cause mortality risk is not known. We aimed to evaluate the separate and joint associations of SES and frequency of sauna bathing (FSB) with all-cause mortality risk in a prospective cohort study. METHODS: We employed the Kuopio Ischaemic Heart Disease Study cohort comprising of 2575 men aged 42-61 years at study entry. Self-reported SES and sauna bathing habits were assessed at baseline. Socioeconomic status was categorized as low and high (median cutoff) and FSB as low and high (defined as ≤2 and 3-7 sessions/week, respectively). RESULTS: During a median follow-up of 27.8 years, 1618 deaths occurred. Comparing low vs high SES, the multivariable-adjusted HR (95 % CI) for all-cause mortality was 1.31 (1.18-1.45). Comparing high vs low FSB, the multivariable-adjusted HR (95 % CI) for all-cause mortality was 0.86 (0.76-0.97). Compared with high SES-low FSB, low SES-low FSB was associated with an increased risk of all-cause mortality 1.35 (1.20-1.51), without significant evidence of an association for low SES-high FSB and all-cause mortality risk 1.07 (0.89-1.29). Positive additive and multiplicative interactions were found between SES and FSB. CONCLUSIONS: There exists an interplay among SES, sauna bathing and all-cause mortality risk in a general Finnish male population. Frequent sauna baths may offset the increased overall mortality risk due to low SES.

Attenuated Risk of Pneumonia Due to Inflammation by Frequent Sauna Baths: A PROSPECTIVE COHORT STUDY.

PURPOSE: Inflammatory pathways are involved in the pathogenesis of pneumonia. Frequent sauna sessions may reduce the risk of respiratory tract infections including pneumonia independent of inflammation. We aimed to evaluate the independent and joint associations of high-sensitivity C-reactive protein (hsCRP) and frequency of sauna bathing (FSB) with risk of pneumonia in a prospective cohort study. METHODS: Serum hsCRP as an inflammatory marker was measured using an immunometric assay and FSB was assessed by self-reported sauna bathing habits at baseline in 2264 men aged 42-61 yr. Serum hsCRP was categorized as normal and high (≤3 and >3 mg/L, respectively) and FSB as low and high (defined as ≤1 and 2-7 sessions/wk, respectively). Multivariable-adjusted HRs (CIs) were calculated for incident pneumonia. RESULTS: A total of 528 cases of pneumonia occurred during a median follow-up of 26.6 yr. Comparing high versus normal hsCRP, the multivariable-adjusted risk for pneumonia was HR = 1.30 (95% CI, 1.04-1.62). The corresponding risk was HR = 0.79 (95% CI, 0.66-0.95) comparing high versus low FSB. Compared with men with normal hsCRP and low FSB, high hsCRP and low FSB was associated with an increased risk of pneumonia in multivariable analysis (HR = 1.67: 95% CI, 1.21-2.29), with no evidence of an association for high hsCRP and high FSB and pneumonia (HR = 0.94: 95% CI, 0.69-1.29). CONCLUSIONS: In a general middle-aged to older male Caucasian population, frequent sauna baths attenuated the increased risk of pneumonia due to inflammation.

Prenatal exposure to elevated maternal body temperature and risk of epilepsy in childhood: a population-based pregnancy cohort study.

Elevated maternal body temperature during pregnancy is of clinical concern as side effects have been reported. We estimated the association between maternal fever and sauna bathing during pregnancy and risk of epilepsy in the offspring. We identified 86,810 liveborn singletons from the Danish National Birth Cohort (DNBC) and followed them for up to 9 years of age. Information on fever including number, timing, level, duration, and symptoms of each fever episodes was collected in two computer-assisted telephone interviews around 17 and 32 gestational weeks; information on maternal use of a sauna was collected in the latter interview, and information on epilepsy was obtained from the Danish National Hospital Register. We applied Cox regression models to estimate the incidence rate ratios (IRR) of epilepsy for children exposed to maternal fever and sauna bathing during pregnancy. Maternal sauna bathing during pregnancy was not associated with an increased risk of epilepsy. Maternal fever during pregnancy in general was not associated with an increased risk of epilepsy in the offspring [IRR = 1.01, 95% confidence interval (CI) 0.85, 1.19], and no dose-response pattern was found according to number, level and duration of fever. However we did find an increased risk of epilepsy among children exposed to at least 3 fever episodes (IRR = 1.88, 95% CI 1.19, 2.98), to maternal fever with symptoms in the urinary system (IRR = 4.86, 95% CI 1.56, 15.17), and to one-day maternal fever of 39.0-39.4°C (IRR = 2.79, 95% CI 1.60, 4.84). Our findings do not support a strong association between hyperthermia and epilepsy but the associations between underlying causes of fever, especially prenatal infections, call for more research.

Sauna as a valuable clinical tool for cardiovascular, autoimmune, toxicant- induced and other chronic health problems.

Sauna therapy has been used for hundreds of years in the Scandinavian region as a standard health activity. Studies document the effectiveness of sauna therapy for persons with hypertension, congestive heart failure, and for post-myocardial infarction care. Some individuals with chronic obstructive pulmonary disease (COPD), chronic fatigue, chronic pain, or addictions also find benefit. Existing evidence supports the use of saunas as a component of depuration (purification or cleansing) protocols for environmentally-induced illness. While far-infrared saunas have been used in many cardiovascular studies, all studies applying sauna for depuration have utilized saunas with radiant heating units. Overall, regular sauna therapy (either radiant heat or far-infrared units) appears to be safe and offers multiple health benefits to regular users. One potential area of concern is sauna use in early pregnancy because of evidence suggesting that hyperthermia might be teratogenic.