Cold Water Survival Time Calculator | Water Temperature Survivability Chart

What is the Impact of Cold Water on the Human Body?

As soon as someone is immersed in cold water, valuable body heat is lost to the external environment. At first, the body may attempt to generate its own heat by shivering, but this is insufficient to counteract the loss of heat. After 20-30 minutes, the core body temperature falls below 35°C (95°F). Once the temperature falls then, the judgment and cognitive functioning of a person will start to fail. An individual exposed to cold water will become increasingly disoriented, become unconscious & then die.

Which mathematical models were specifically developed to forecast survival times?

To predict survival times in cold water, two mathematical models have been developed by Hayward et al. (1975) & Xu & Giesbrecht (2018).

Hayward et al. evaluated the effects of immersing people in the sea for a series of exposure tests. The research subjects were average-sized people wearing light clothing and wearing life vests. Assuming the average person loses consciousness when the core body temperature reaches 30°C, the predicted survival duration was calculated.

This formula is used when the water temperature is above 0 °C.

Survival Time (minutes) = 15 + 7.2 / (0.0785 − (0.0034 × water temperature °C))

Based on 122 cases reported in the UK National Immersion Incident Survey, Xu & Giesbrecht (2018) developed their proposed calculation. This formula is used when the water temperature is 0 °C or below 0 °C.

Survival Time (hours) = 0.0547 × (water temperature in °C) 2 + 0.5048 × (water temperature in °C) + 1.3604

Water Temperature Survivability Chart

This is a chart of expected Survival Time in Cold Water.

Water Temperature	Exhaustion or Unconsciousness	Expected Survival Time
>80°F (>26.7°C)	indefinite	indefinite
70–80°F (21–27°C)	3–12 hours	3 hours – indefinite
60–70°F (16–21°C)	2–7 hours	2–40 hours
50–60°F (10–16°C)	1–2 hours	1–6 hours
40–50°F (4–10°C)	30–60 minutes	1–3 hours
32.5–40°F (0–4°C)	15–30 minutes	30–90 minutes
<32°F (<0°C)	under 15 minutes	under 15–45 minutes

Cold Water Immersion Chart

Here, readings are taken while wearing different dry suits. A drysuit is a kind of wearable tight fit clothing that is airtight & waterproof, specifically designed for divers.

Here, time is in minutes & is recorded till a person is in high exhaustion & on the brink of unconsciousness.

Temperature of water	Drysuit only	Drysuit + liner	Drysuit + underwear	All
35 °F (1.66 °C)	≤60	≤90	≤105	≤195
40 °F (4.5 °C)	≤60	≤105	≤135	≤255
45 °F (7.2 °C)	≤90	≤150	≤180	≤315
50 °F (10 °C)	≤105	≤195	≤225	>360
55 °F (12.7 °C)	≤150	≤270	≤315	>360
60 °F (15.5 °C)	≤210	≤360	>360	>360
68 °F (20 °C)	≤360	≤360	>360	>360

How to Calculate Cold Water Survival Time When a Person is Submerged in it?

First, we will have to determine the temperature of the water.
Depending on the temperature of the water, we can determine which formula to use.
If the water temperature is 0 °C or below 0 °C, we will use the formula given by Xu & Giesbrecht. If the water temperature is above 0 °C, then we will use the formula given by Hayward et al.
After the calculation, we will get the approximate survival time of a person immersed in cold water.

Begin by utilizing a few more calculators, then visit Arithmetic Calculator for reading computations and equations for a variety of themes.

Solved Example to Calculate Survival Time in Cold Water

While travelling on a boat, a person accidentally falls into the sea. People from the boat called the rescue team. So, how much time can this person survive in the sea if the temperature of the water is 5 °C?

Solution:

Here, the temperature of the water is more than 0 °C. We can use the formula given by Hayward et al.

Survival Time = 15 + 7.2 / (0.0785 − (0.0034 × water temperature °C))

Put temperature as 5 °C, and then calculate the time

Survival Time = 1 hour & 57 minutes

The estimated survival time for a person is 1 hour & 57 minutes.

FAQs on Cold Water Survival Time Calculator

1. How long can you stay in 35-degree water?

In 35-degree water, a person can survive for one to 1 1/2 hours.

2. How long can you survive in 70-degree water?

In 70-degree water, a person can survive for 2 - 40 hours.

3. How cold was the water when the Titanic sank?

When the Titanic sank the water temperature was around -2.7°C.

4. Is swimming in 60 degrees water safe?

It becomes very difficult to control breathing in water temperature between 60 to 70 degrees. Thus, it is very dangerous to swim in water at 60 degrees of temperature.