The purpose of this study is to compare two novel active rewarming techniques in mildly hypothermic people. Volunteers will undergo 3 cooling trials in a circulating bath at 14 degrees celsius and will then be rewarmed with either shivering alone, warmed iv fluids (IVF), or water perfusion pads applied to the hands and feet. The investigators hypothesize that both heated IVF and water perfusion pads to the arteriovenous anastomoses (AVAs) will prove to provide significantly superior rewarming rates than shivering alone.

Inclusion Criteria:

• Any healthy male or female over 18 years of age

Exclusion Criteria:

• No heart/blood pressure/cholesterol medications.
• No history of Raynaud's disease or any other condition (including asthma) that could be aggravated by cold-water immersion