Both saunas and cold water ther­apy have their place.  Although it seems relax­ing and ther­a­peu­tic, a post-hike hot tub, sauna, or heat­ing pad is not always rec­om­mended.  After a lengthy hike or any extreme work­out, your joints and mus­cles are inflamed. If you put heat on them, the blood flow to those areas will increase, which can make them even more inflamed. In addi­tion, you may already be slightly dehy­drated, and the addi­tional heat and sweat­ing may dehy­drate you even more.

An icy soak, on the other hand, will help reduce inflam­ma­tion of tis­sues and joints, relieve sore­ness, and speed up your recov­ery. There are two ways to accom­plish this.  First, sim­ply fill a bath tub with cold water and get in, so your body can adjust to the tem­per­a­ture. Then dump in ice (as tol­er­ated). Stay in the tub for 10 min­utes.  If this is too extreme at the begin­ning, you can work your way up with a cold shower.  Grad­u­ally decrease the temp of the water so your body can adjust.  The rec­om­mended approach is to start with a five-minute grad­ual adap­ta­tion and decrease in water tem­per­a­ture until the water is around 68 degrees — 2 to 3 min­utes once or twice daily at this tem­per­a­ture will give you many of above ben­e­fits.  At the very least, there is the more tra­di­tional route of putting bags of ice or frozen veg­eta­bles on the sore or inflamed parts for 10 to 15 min­utes post-training.

Ben­e­fits of Cold Water Ther­apy
    •    Improves cir­cu­la­tion. Effi­cient blood cir­cu­la­tion speeds up recov­ery time from stren­u­ous exer­cises.  Alter­nat­ing between hot and cold water while you shower is an easy way to improve your cir­cu­la­tion. Cold water causes your blood to move to your organs to keep them warm. Warm water reverses the effect by caus­ing the blood to move towards the sur­face of the skin.
    •    Relieves depres­sion. Research at the Depart­ment of Radi­a­tion Oncol­ogy at Vir­ginia Com­mon­wealth Uni­ver­sity School of Med­i­cine indi­cates that short cold show­ers may stim­u­late the brain’s pri­mary source of nora­dren­a­line — a chem­i­cal that could help mit­i­gate depres­sion.
    •    Keeps skin and hair healthy. Hot water dries out skin and hair. Cold water can make your hair look shinier and your skin look health­ier by clos­ing up your cuti­cles and pores.
    •    Strength­ens immu­nity. Accord­ing to a study done in 1993 by the Throm­bo­sis Research Insti­tute in Eng­land, indi­vid­u­als who took daily cold show­ers saw an increase in the num­ber of virus fight­ing white blood cells com­pared to indi­vid­u­als who took hot show­ers. Researchers believe that the increased meta­bolic rate, which results from the body’s attempt to warm itself up, acti­vates the immune sys­tem and releases more white blood cells in response.

Ben­e­fits of Sauna
Saunas offer many ben­e­fi­cial effects as well–particularly after the 36–48 hour post-hike win­dow.
    •    Saunas induce per­spi­ra­tion, which helps the body get rid of the toxic by-products that are pro­duced dur­ing exer­cise. This takes some of the load off of the kid­neys which have to work over­time to do this detox­ing action in other ways. 
    •    Saunas also increase cir­cu­la­tion and raise body tem­per­a­ture, which helps the body fight aches and pains. Stud­ies also show saunas are effec­tive in help­ing to relieve mus­cle ten­sion. This can mean quicker recov­ery between work­outs.

When using the sauna, make sure that you begin with mod­er­ate heat and adjust the heat when nec­es­sary.  Don’t drink alco­holic bev­er­ages before you enter the sauna. This increases the chance of dehy­dra­tion.  Make sure to replen­ish flu­ids after your sauna ses­sion.  Try to wait 36 to 48 hours after a dif­fi­cult train­ing ses­sion before going to the sauna or hot tub.  If you’re train­ing in the morn­ings, in par­tic­u­larly cold con­di­tions, or are a bit stiff going into a work­out, a short (less than 5 min­utes) time in the hot tub, steam room or sauna can help warm you up, or loosen up mus­cles prior to stretch­ing. That doesn’t mean you can use this as your workout-specific warm up and you may need addi­tional hydra­tion as a result.

Some con­di­tions require you con­sult your physi­cian before you enter a sauna or take a cold shower. If you are preg­nant, have high blood pres­sure, fever, or heart dis­ease; you should con­sult with your physi­cian before using either. The extreme tem­per­a­tures can cause stress to the body when the body is bat­tling an ill­ness.