Most people take off their watches and jewelry at night, and there are many health benefits to sleeping naked, including a better night’s sleep and weight loss. But with wearable technology now able to track vital signs, like heart rate and movement, around the clock, should we be making an exception for health and fitness devices? It’s a personal decision and the main thing is do get a good, comfortable night’s sleep, but there are some important reasons to keep recording your data even at night.

Most fitness bracelets and smartwatches have sleep tracking functions, which obviously only come into their own at night. These not only let you know if you have had a good night’s sleep, they can also be set to wake you at the optimal time. Restlessness at night can be a strong sign of anxiety, depression and poor general health, so it can also be useful to have the data to see why you are not feeling yourself in the morning. However, not all sleep trackers are wearable devices, so if this is the main function you are looking for, why not check out these devices. Be warned, however, that some of these devices only work if you sleep alone.

If you already have a smartwatch, you might not want to invest in a new device just to track your sleeping activity. In this case, work with what you have and test the various functions of the device with a variety of apps. There are plenty out there for Android and iOS and they all offer similar features, including the ability to monitor the effects of caffeine, tobacco and alcohol on your sleep. Read about the best of the bunch here.

If you haven’t caught the smartwatch bug, a fitness tracker might be the better option. It can be worn around the clock and also monitors your heart rate both during strenuous exercise and at rest, so some of the more discreet and comfortable devices could be just the thing. One very sleek device is the Jawbone UP3, which pairs with an app that provides exercise tips by day and sleep assistance at night.

There are obvious health benefits to getting a better night’s sleep and all these devices, whether wearable or not, can help you do that by raising awareness and increasing motivation. After all, sleep loss can lead to serious health problems, such as heart disease, high blood pressure, stroke, diabetes and much more besides. So the more aware people are about the importance of a good night’s sleep, the better.

Apart from the discomfort of wearing devices at night, there are no serious drawbacks as the RF radiation of the Bluetooth transmitter is very low powered and completely harmless. Even users with pacemakers need not worry about any interference.

In addition to the benefits of tracking sleeping patterns, there are other reasons to track people’s sleep, particularly at night. As we get older, however, we come under increasing danger of suffering strokes, heart attacks and other complications. Many people who suffer ischemic strokes have them at night, which often stops them getting timely access to medical treatment. According to researcher Jason Mackey, MD, of the University of Cincinnati:

“Because the only treatment for ischemic stroke must be given within a few hours after the first symptoms begin, people who wake up with stroke symptoms often can’t receive the treatment since we can’t determine when the symptoms started.”

Clearly, tracking sleep for those at risk of stroke can be incredibly useful.

The story is similar when it comes to heart attack, which takes more lives each year than anything else. In the words of Roberto Manfredini, professor of internal medicine at the University of Ferrara in Italy:

“The most dangerous times for heart attack and for all kinds of cardiovascular emergency — including sudden cardiac death, rupture or aneurysm of the aorta, pulmonary embolism and stroke — are the morning and during the last phase of sleep. A group from Harvard estimated this risk and evaluated that on average, the extra risk of having a myocardial infarction, or heart attack, between 6 a.m. and noon is about 40%. But if you calculate only the first three hours after waking, this relative risk is threefold.”

So it makes sense that tracking sleep activity, particularly heart rate variability, among those at risk of these deadly events is not only healthy, it can be life-saving. And should such an event occur, it is also important that the emergency services can be alerted even if the person is alone and unable to act due to their precarious condition. Some companies are already working on devices to not only measure vital signs of patients 24 hours a day, but also to provide services that facilitate rapid response should the data show that something serious might be wrong. When this technology finally arrives on the market, there will be no doubt about the health benefits of keeping wearable devices on even at night.