# Wolfram Function Repository

Instant-use add-on functions for the Wolfram Language

Function Repository Resource:

Compute the approximate survival time of a human in cold water

Contributed by:
Claudio Lobo Chaib Filho

ResourceFunction["ColdWaterSurvivalTime"][ estimates the survival time in cold water for a temperature | |

ResourceFunction["ColdWaterSurvivalTime"][ gives the property |

ResourceFunction["ColdWaterSurvivalTime"] is useful to inform how long a person can survive hypothermia.

Any temperature quantity is accepted by the function. If the argument is not a Quantity, it is interpreted as "DegreesCelsius".

The temperature values *temp* accepted by the function must be in the temperature range 0 to 20 degrees Celsius.

Available properties include:

"SurvivalTime" | time a human can survive in cold water of the specified temperature |

"MetabolicHeat" | heat generated by the body in the cold water |

"CoolingRate" | body's cooling rate |

"Plot" | plot of the curve of survival time versus water temperature |

"PropertyAssociation" | all results as an Association |

ResourceFunction["ColdWaterSurvivalTime"][*temp*] is equivalent to ResourceFunction["ColdWaterSurvivalTime"][*temp*,"SurvivalTime"].

The "Plot" property shows the survival time curve. The *x*-axis is the water temperature and *y*-axis is the survival time. The input *temp* is displayed as a red point.

ResourceFunction["ColdWaterSurvivalTime"] accepts the options:

"EnergyUnit" | "Calories" | unit of the result heat ("Kilojoules", "Watts", …) |

"TimeUnit" | "Minutes" | unit of time in the results |

Get the survival time in cold water at a specific temperature:

In[1]:= |

Out[1]= |

The function interprets any unit type of degrees for temperature:

In[2]:= |

Out[2]= |

The function used with one argument is similar to the function with two arguments where the second is "SurvivalTime":

In[3]:= |

Out[3]= |

In[4]:= |

Out[4]= |

If a Quantity is not specified, it is interpreted in "DegreesCelsius":

In[5]:= |

Out[5]= |

Obtain the heat generated by the body in water at the specified temperature:

In[6]:= |

Out[6]= |

Obtain the body’s cooling rate for a specific temperature:

In[7]:= |

Out[7]= |

Use "Plot" to obtain the survival time curve (*y* axis) for different water temperatures (*x* axis):

In[8]:= |

Out[8]= |

Use "PropertyAssociation" to get all the information simultaneously for a specific temperature. Note that the result is given in the same temperature units as the input:

In[9]:= |

Out[9]= |

Get information using another unit of heat with the option "EnergyUnit":

In[10]:= |

Out[10]= |

Choose another unit of time with the "TimeUnit" option:

In[11]:= |

Out[11]= |

Change both the unit of energy and the time. The plot and the result use the chosen time unit and a given requested energy unit:

In[12]:= |

Out[12]= |

Note that even if the temperature unit is not degrees Celsius, the *x* axis of the graph remains in that unit:

In[13]:= |

Out[13]= |

If the required property does not contain information about the energy, the "EnergyUnit" option does not influence the output:

In[14]:= |

Out[14]= |

- Cold Water Survival–United States Search and Rescue Task Force (USSARTF)
- Hypothermia: Understanding and Prevention–Minnesota Sea Grant, University of Minnesota

- 1.0.0 – 29 September 2020

This work is licensed under a Creative Commons Attribution 4.0 International License