传统芬兰干式桑拿通常处于 160–200°F（70–100°C），推荐时长约 8–10 分钟、每周 3–4 次，并以 20 分钟为上限以避免脱水与过热。红外线桑拿温度较低，为 120–150°F（50–65°C），多数建议停留 20–30 分钟，但安全范围仍以 20 分钟内为宜。桑拿的生理负荷包含心率、体温与心排量上升，产生类似中等强度运动的效应；若感觉头晕或恶心需立即离开。具有心脏、肾脏、血压或呼吸系统问题者及孕妇应避免使用，以减少热应激风险。

体能水平显著影响耐热时间。研究指出，经常桑拿可提升耐力表现：一项为期三周、针对男性耐力跑者的实验显示，运动后桑拿可增加血容量并延长至力竭时间，反映适应性改善。适应力亦受基因影响，但频繁暴露可提高耐受阈值。对不适应高温者，可采用对比疗法，通过在高温与低温（例如冷浸或冷冻疗法）间快速切换，促使血管反复收缩与扩张，改善循环、降低炎症并增强恢复能力。

热与运动结合可进一步扩大益处。哈佛医学院研究显示热瑜伽可能减轻抑郁症状，说明热环境与温和动作协同产生心理与生理增益。热促使肌肉放松并扩大关节活动范围，从而降低拉伤风险。即使空间有限，在桑拿内进行轻量动作如鸽式、眼镜蛇式、桥式与前屈等，都能在温热状态下更温和地加深伸展，使柔韧性与调节能力提升。

Traditional Finnish dry saunas typically operate at 160–200°F (70–100°C), with recommended sessions lasting 8–10 minutes, three to four times weekly, and an upper limit of 20 minutes to avoid dehydration and overheating. Infrared saunas run at lower temperatures of 120–150°F (50–65°C), with suggested durations of 20–30 minutes, though remaining under 20 minutes is generally safer. Physiological load includes elevated heart rate, core temperature, and cardiac output, mimicking moderate exercise; users must exit immediately if lightheaded or nauseous. Individuals with cardiac, renal, blood-pressure, or respiratory issues, as well as pregnant users, should avoid heat exposure.

Fitness level strongly influences heat tolerance. Evidence shows regular sauna use improves endurance: in a three-week study of male distance runners, post-training sauna sessions increased blood volume and time to exhaustion, indicating adaptive gains. While genetics modulate tolerance, repeated exposure increases capacity. For those less heat-tolerant, contrast therapy—rapid alternation between heat and cold—induces vascular contraction–dilation cycles that enhance circulation, reduce inflammation, and improve recovery.

Combining heat with movement amplifies benefits. Harvard Medical School research links hot-yoga practice to reduced depressive symptoms, illustrating synergy between heat and mindful motion. Heat softens muscles, enlarges joint range of motion, and lowers strain risk. Even in limited space, gentle poses such as Pigeon, Cobra, Bridge, and Forward Fold become more accessible in warmth, enabling deeper, controlled stretching that enhances flexibility and self-regulation.