There are a number of potential hazards involved in the use of weighted items, such as blankets and vests.
On April 18th 2008 Gabriel Poirier, a young autistic boy, died in the province of Quebec after being wrapped in a weighted blanket by a teacher in a classroom. Following this tragedy, Coroner Catherine Rudel-Tessier, made the following recommendations,
“Because the therapeutic value of weight blankets does not seem to be proven scientifically, and because of the fact that they pose a risk for children's lives, we could be tempted to prohibit their use altogether. However, I believe that it is possible to manage usage in a strict manner in order to minimize the danger. I believe that certain ground rules must be respected by those who wish to use this sensory pressure technique, namely:
Stephenson and Carter (2008) expressed some concerns about the potential harm from wearing weighted vests for prolonged periods, suggesting that the effects are unknown.
“The effect of prolonged wearing of a weighted vest needs to be considered. It is recommended that children carry no more than 10-15% of their body weight in a backpack and recent research evidence indicates that 10% is a safer limit. While the weight in a vest is more evenly distributed than in a backpack, the maximum weight used in the studies was at the upper end of the safe range. While a vest was worn for a maximum of 2 h at a time in studies in the current review, it has been reported that they can be worn for up to 4 h at a time and for most of the school day. Clearly, these are much longer periods than a backpack would typically be carried by a child. One issue that does need consideration is the effect per se of carrying this amount of weight, suspended above the centre of gravity, particularly for an extended period of time. If vests do have effects, and the evidence on this point remains unconvincing at this stage, it is possible that these may be artifacts of fatigue and unrelated to purported sensory integrative mechanisms.”
There are no known contraindications for weighted items - something which makes a particular treatment or procedure potentially inadvisable for a specific group of people.