You Can Challenge Your Self by Yourself or you can Invite one friend or two to plunge yourself in the Coldest Bath and discover your ability to remain calm in the Cold.

When you go from the Confort of the Warmth to the Disconfort of the Cold, and again back to the confort of the your Body releases Dopamine and gives you this feeling 

Many athletes are known to take ice baths after training to lower inflammation, improve circulation, and reduce lactic acid build-up.

Hot and cold therapy may be effective in aiding recovery by reducing levels of both lactic acid and muscle soreness.

It may be particularly beneficial for those who have a second workout planned for later in the day, as it doesn’t shut the body down in the way pure ice therapy does.

Contrast therapy 

will relieve pain and swelling associated with a variety of injuries. It’s most effective to treat pain in the hands and lower body. ( Image Reference)

This versatile treatment can be used for a variety of conditions, including:

Strains and sprains of the foot, ankle, elbow, knee, wrist, neck, or shoulder
Alternating hot & cold therapy for lower back pain
Swelling (once the acute stage has passed)
Muscle spasms
Joint aches
Repetitive-strain injuries, such as tendonitis or tennis elbow
Sports injuries
Flare-ups of chronic conditions, such as arthritis or fibromyalgia
Some pains associated with cancer
Any other injury that causes swelling or aching
Chronic lower back pain may or may not respond to contrast therapy—many sufferers find they enjoy greater relief from all-day heat wraps.

Although the hip joint causes problems for many, it is not usually the best candidate for contrast therapy due to its size and the fact that it is often padded with fat. However, given the simplicity and cost effectiveness of hot and cold therapy, it’s worth trying contrast therapy for many conditions that cause pain.

However, 

there are some situations when contrast therapy is not recommended. Avoid it if you have:

An acute injury
Injuries that have occurred recently (within the last three days) should not be treated with heat or contrast therapy, due to the effect of heat on inflammation. Ice is best in the days after injury, after which time contrast therapy can be used.

An open wound or skin issues
The therapy may cause bleeding or increase the risk of infection in those with burns, boils, cysts, cuts, scrapes, or sunburn.

Circulatory and heart conditions
Those with low blood pressure, poor circulation, or heart conditions may react adversely to extreme heat or cold.

Cold urticaria

Fever or infection
Heat application may not be suitable for those who are already feeling warm due to fever or infection.

Peripheral neuropathy/diabetic neuropathy
Since it can be difficult to feel pain with this condition, you may not be aware if you are burning your skin with ice or heat.

Raynaud’s syndrome
Cold treatments would adversely affect this condition, which is characterized by constricted blood vessels in colder temperatures.